If you know how to sew, then you need to stop reading now.
But if hemming a curtain seems just out of your reach, then read on! I promise it is not hard at all, although it takes a bit of time. I am not a great sewer, not even a good one, and I am not gonna teach you a super professional way to whip up a hem. But my method works and is especially useful if you are of the not so patient variety.
My hemming project is to shorten the curtains in my oldest's room. He has 6 altogether and their length was making the whole room feel heavy.
Wash and dry the curtains in question.
Rehang the curtain.
Mark where you want the bottom of the curtain to hang to. You should really pop a pin in, but I just hold it in that spot.
Fold the curtain up at the mark and double check that it is straight by comparing the fold at both ends of the curtain.
Iron the fold.
Cut off the excess fabric leaving enough to turn under.
Take a minute to fold up the excess as you go so that if you are doing a big job you don't have a whole bunch of clean up at the end.
Fold fabric under. You should really use pins here too but I hate them so I just make sure to hold the fold in place.
Sew alone the top edge of the fold.
Don't forget to do a little reverse at the beginning and end of your hem.
Put up your first curtain to make sure it hangs at the right spot. If it does, use it as a guide to measure the rest.
And there you have it.