Step 1 Measure the height and width of the window you will be making curtains for. This is done by measuring the exact width and the height is measured from where the curtain rod is or will be, down to where you want your curtains to end. Add 5 and 1/2 inches to the height for fabric. This is how much fabric you need. (With bedroom and bathroom curtains, I simply use the width of the fabric for one curtain panel, this is 44 inches wide usually. If the window is 2 and a half feet tall, I basically need 2 yards of fabric. For wider windows, sew widths of fabric together at finished edges.
Step 2 Choose a fabric. Lighter sheet like fabrics are great for kids rooms. It's cheap and washes easily. Living rooms could have something thicker like curtain or upholstery fabric.
Step 3 Cut fabric to appropriate lengths and widths (don't forget small windows can just be the width of the fabric for each panel). If you are doiing 2 panels, just cut fabric in half so instead of one 3 yard piece you have 2 one and a half yard pieces.
Step 4 If fabric has a finished edge that does not change color, it can be left as is. If it changes color or has an artists signature, you will want to hem this in. Usually about 1/4 inch.
Step 5 Press and hem 1/4 inch on top and bottom of each panel. Sewing the hem in this step can be eliminated after understanding the basic pattern we follow. You will only need to press it under on future curtains you make.
Step 6 On the bottom of each panel, press in 2 inches. Fold corners in making 90 degree angles on each side. One side of corner is exactly matched to the pressed hem line. (Think of wrapping paper). Sew along same line that the 1/4 inch hem was sewn on but also adding the turn where the corners are folded in.
Step 7 Fold tops of panels under 3 inches and press. Now one inch from the fold, sew a straight line across the top. Now sew a second line following the thread from the quarter inch line you had sewn in step 5.
Step 8 Press the full curtain and hang by placing rod between the 2 sewn lines in the top of the curtain. This leaves a decorative inch of fabric above the rod.
Variance For Puffy Curtains Add about a foot to the length of the fabric (give or take depending on the amount of 'puff' you want. Follow all the same steps above.
Where the tie backs would normally be, hang a cup hook on the wall. Tie curtains loosley with ribbon about a foot lower than the cup hooks. Lift tied area and hang on the hook. Puff and arrange the curtain just above the ribbon. If the fabric is heavy and falls, stuff with some tissue paper.
Once you get the basics down you will be designing all sorts of curtains in no time. Ballon curtains are basically the same design but with less length and the bottom 1/4 inch hem is isnt folded another 2 inches. It is folded almost in half. The bottom is brought up to meet the seam (not the fold line). It meets the same line as the quarter inch hem you went over twice on the top. Curtains are filled with tissue paper.