First you need to work out how much fabric you need. Measure the width of your rail or curtain pole (ignoring any exciting finials at the end). Multiply that width by 1.5. Each of your finished curtains will be 1.5 times the width of the pole. Then measure the finished length of your curtain by measuring from either the top of the rail if you are using curtain rails of the Swish type or from the bottom of the pole if you are using traditional curtain poles to the place where you want your curtain to fall. All my windows use curtain poles so these instructions are designed for curtains which hang on poles. This is the finished length so add 10 cm for the bottom hem and 5 for the top and that will tell you how long each piece of material needs to be.
If you are using a plain material that is all you need to know in order to work out how much fabric to buy. If you are using a pattered fabric you need to work out the repeat of the pattern so that you can ensure that when your curtains are hung the pattern on one curtain matches up with the pattern on the other. When I first started curtain making I was quite daunted by this so the first few pairs I made used only plain material. That was daft looking back as matching pattern repeats is not difficult. This website here has a very good calculator for working out how much material you need including pattern repeats. Because they give you a larger allowance for hems than I normally use you will buy rather more material if you use this calculator but no more than enough to make a couple of cushion covers with and it does make calculation very quick and easy.
So now you are ready to go shopping. Along with your patterned material you need to buy curtain lining, curtain header tape and thread.
I normally use quite a deep header tape like this with three cords unless the window is quite small when tape with two chords would be enough. A deep tape like this also copes well with longer curtains and heavier material.
Other things which are useful are a tape measure, plenty of pins (I like the headed kind as I don't prick myself so much) and a really good pair of cutting out scissors kept for cutting nothing but material.
The other very useful thing you can see here is a piece of your material kept for testing that your stitch length and tension are right whenever you rethread your machine or bobbin. I always test a newly inserted bobbin by sewing a test line or two on a piece of waste cloth. This comes from many frustrating experiences of merrily sewing away on my finished article only to find that the stitching was puckered or wrongly tensioned.
So the shopping is the fun bit. Make sure you buy enough thread and enough tape. Running out of either is a real pain. Bring it home. Gloat over it. Hold the material up by the window and imagine how lovely it will look. Have a cup of tea.
Then if you are like me nothing will happen for a few weeks. In my experience leaving your project for a few weeks or even a few months is OK. If you find everything has been sitting upstairs for a year or so just making you feel guilty that is more of a problem! There seems for me at any rate to be a point when the fact that something hasn't been done means it will never be done.
Then one weekend or nice clear day take it all out and get going.
Another very useful thing to have is a nice large bit of floor space to lay out the material for cutting and later for pinning. The more you can get things totally flat the easier the job will be so it is worth moving furniture and putting up with the getting up and down to the floor and working on your hands and knees to have a totally flat area on which to work. Lay out the material and measure your first length of curtain. If the width of your material is within 10cm of the 1.5 times width you need for the curtain (either narrower or wider) I would use the material width and not bother to cut it down or add another piece. Most furnishing material is 140 cm wide and that is often fine for smaller windows.
Measure again. I don't know whether "measure twice, cut once" is a carpenter's saying or a dressmaker's one but it is hugely true. There are lots of mistakes you can put right in making curtains, but if you cut the fabric wrong in the first place that can be a disaster.
When you have cut your first curtain, turn the material so that the right side is facing you if it is wasn't already. Find a distinctive part of the pattern and lay your uncut material on top, matching the pattern on the top piece exactly with the pattern on the bottom piece. If the material has a clear top and bottom make sure both pieces are the same. You do not want birds standing on their heads. You may hear the weary voice of experience here. Cut your second curtain to match the length of your first. Cut two pieces of lining material to the same length minus 10 cm. If your lining material is as wide as your curtain material, cut a strip 5cm wide off the width so that you end up lining material that is 10cm shorter and 5 cm narrower than the curtain pieces.
Along with the various things that help with this job, there are of course things that don't help: cats for one.
Wine is another. Even the leisurely single glass you think you can have while you get on with pinning up hems and sides is a glass too many. I don't know why breathalyser tests can't be replaced with knitting and sewing challenges. I think they would be far more sensitive to alcohol consumption. You are already doing something which will go wrong if it can. Sewing is one of the few activities where a glass of wine does not help. You can let the cat and the wine back into the room when you decide to pack up for the evening.
Lay the fabric right side down on the floor and pin up the bottom 5cm in a nice straight line. Fold that 5cm over again, take out the first pin and repin with a double hem. If you forget to take the first lot of pins out and simply use some more pins to make your double hem you will end up with a line of pins hidden in the bottom of the hem which will be a total pain to get out. Some you might never manage to extract and they will prick you and annoy you when you are blithely opening the curtain many weeks later.
Pin up the other curtain with the same double hem and place one curtain on top of the other to check that you still have two pieces of fabric the same size and that the pattern repeats still match. It sounds nerdy to check but it is easy to fiddle about with the pins if you got it a bit wrong. Take the curtains away and sow the hems on the machine. Do exactly the same with the lining material, producing a machine sewn double hem on each piece. Bring everything back to your nice big floor space again.
Lay the curtain flat, right side uppermost. Lay the right side of the lining material on top, matching along one side and leaving 5cm of the curtain material showing below the bottom edge of the lining material. Sew with a 1.5cm seam. The sharp eyed person might notice that it looks as though the side seam has already been sewn here and then unpicked. You would be right. After more years of sewing that I care to admit to I failed to sew the right sides together and had to take it apart and turn the lining material over. Your machine probably comes with a small spiked tool with a plastic handle called a stitch unpicker. It is your friend. When you make a mistake it is almost always better to say "Drat" and unpick it than it is to try to persuade yourself that you can get away with it. I used to think I wouldn't notice my mistakes as time went by but what I have found is that I never forget them and, worse still, I can't resist pointing them out to other people who are trying to say nice things about my work. Make a soothing, yoga type "Ommm" noise to yourself and take it back.
Sew the lining and the curtain together down one side. Your lining will be shorter than your curtain at both top and bottom. Lay the material down again and pin the lining down the other side. Because your curtain and your lining materials are different widths you will need to create a fold in the wider material so that you can line up the lining and curtain materials. Sew down this side with a 1.5cm seam. You will now have a tube of material, hemmed at the bottom. Turn it inside out so that the curtain material is the right side out. Lay it flat on the floor again, lining side uppermost, and smooth it flat so that where your curtain material shows on either side you have identical widths. When I am adopting a counsel of perfection, I iron the curtains at this stage.
You are nearly there now. I don't always follow my own advice but it is often a good idea to stop for the day if you have been sewing for a while. On the "If it can go wrong, it will" basis, a whole variety of possible disasters are just waiting to happen. Your bobbin will run out just before you reach the end of the last possible line of stitching. You will cut the header tape too short. You will somehow manage to sew the top of the curtain to the bottom. Reader, I have done all of the above in my time. Sewing late into the night increases your chances of getting it wrong almost as much as the glass of wine. Come back to it tomorrow.
Now we get to putting on the header tape. Lay the curtain flat again, lining side uppermost. You will have around 5cm of curtain fabric showing above the top raw edge of the lining material. Measure the curtain and place a line of pins, around 18cm apart to show you where the finished top edge of the curtain will be. Fold in the top corner of the curtain fabric in a neat mitre and pin the curtain fabric along the line of the pins so that the curtain fabric overlaps the lining. Check again that you have a curtain of the right finished length before you go any further. Measure twice, sew once is also a good thing if you can manage it!
Lay the curtain header tape along the top edge of the curtain overhanging the curtain sides by about 10 cm on either side. You are going to tie the chords together at one end, having pulled them out of around the 10 cm of tape. I find it easier to tie the middle chord to an outside one and then both of these to the remaining chord. When you have done that, fold the tape so that the tied chords are covered by the header tape and begin to pin the tape along the top edge of the curtain. When you get to the other end, pull out the loose chords so that they line up with the edge of the curtain and fold the remaining tape under as you did at the beginning. Take it to the machine and sew the line along the top of the curtain, taking the pins out as you go. Return to the end with the hidden tied chords and sew up and down the end of the tape so that the chords are secured by the line of sewing. Leave the end with the pulled out chords open. You won't need to pin the bottom edge of the header tape to sew it but it is a good idea to start at the same end you started with for the top edge. You get a neater, straighter attachment by doing this than you do if you sew across one way, down the tied end and along the other edge in the other direction.
When you attach the header tape to the second curtain, make sure that you have your tied ends and your loose chords at the opposite ends to those you used on the first curtain. This means that when you hang your curtains and pull up the chords the pulled up chords sit at each side of the curtain, at the edge by the window frame, not in the centre of the window.
You are done. Iron the curtains on the lining side.
If you can't hang them straight away keep them smooth with the lining side out in case of flying coffee and cat hairs. I can't show you them hanging right now as we still have visitors in the cottage but I have two pairs of shorter curtains and two floor length ones made and ready to go. This gives you an idea of a finished short curtain, laid out on the bed.
Congratulate yourself. Marvel at the money you have saved. Allow yourself that glass of wine. Start to plan your next project
So here they are! It worked! It worked!