Y'all know I'm not the greatest DIYer out there, so if I did it myself, you can too! A few weeks ago I bought fabric to have drapes made for our dining room. I had a seamstress make them, and she did a great job, however, in my haste, I measured wrong (too long) and did not buy fabric for her to line them with. I guess I thought I could skip that step, but once they were hung, I realized they really needed to be lined because the fabric is a loose weave, and you could see the blinds through them during the day.
See what I mean? Ug!
I wanted a cheap, quick solution, so I made a curtain liner out of a twin-sized Target bed sheets. I think they were $10 each. Last time I bought fabric liner from Joann's, I think it was $5 a yard on sale. These sheets are thin, so if you want a heavier liner, I'd go with a thicker fabric.
The twin sheet width was wide enough to cover the width of the curtains, but about a foot too short (we have 10-foot ceilings in this room). Since the window doesn't go all the way to the floor, you can't tell that the liner doesn't extend all the way to the floor.
I lay the sheet on top of the drapes and used no-sew tape to iron the pieces together. I started along the top, then did each side, leaving the bottom alone.
I also "no sewed" the hem to make the drapes the proper length. Much better!