Leggings are easy and cheap to make. All you need is tall women’s socks, some thread, and about 15 minutes (for the first pair). By the way, I used 1/4" seams and zig-zag stitched.
Cut a section out of the foot portion 5"x 2.5" on fold. You will end up with a rough 5" square; these will be your cuffs. Note, I typically cut this from the bottom of the foot, but these socks really slanted so I went from the top.
Fold the cuffs so that the pattern of the leggings match the cuffs. I've messed this one up a few times so make sure it's how you like it.
The top cuff is still showing the direction I want it when it's on the legging. On the bottom cuff I opened it up leaving Top A up and folding the sides together. Zig-zag stitch down "sides" creating a tube.
Turn the cuff in half so that Top A & B are up and the wrong side of fabric is together. Sorry, the it's blurry!
Slip the cuff over the legging matching the seam up with one of the pressed sides of the legging. The cuff will be smaller then the legging so you must stretch it out to pin it down; you must also do this when zig-zag stitching them together.
Your finished!
Here she is at 1.5 years old wearing her leggings. As you can see she wasn't a very willing model; she was taking them off.
These are also great for travel! We were driving from England to Germany when at one gas stop we realized the temperature had dropped. We slipped the leggings on her and she was good to go. She was 1.5 years old in the photo wearing a pair of white leggings. She still wears both pairs of leggings at 3.5 years old. I've read they can wear them until they're about 7.