I've seen a couple of tutorials for making skinny jeans from flare jeans, So I decided to try it out on my daughter's jeans that are getting a little short on her. This way she can tuck them in her boots this fall!
1) Start with a pair of regular flare or boot cut jeans in your child's size.
2) Have her try them on inside-out, and pin the sides to see where you want to sew them.
**Something I figured out-If the jeans have a faded wash, then you'll want to pin them on both sides of each leg, that way you won't have the darker side of the leg going down in a funny diagonal line. If your jeans have no fading to them, then pin the inner side of the leg, so that you'll still have the professional looking seam on the outside.
3) Draw a line along the leg where you've pinned it with a pen or marker.
4) Sew all the way down, about 1/2 inch outside your line (toward the outside of each leg) to allow for seams. If in doubt, go wider rather than more narrow, because you can always sew it again and make the leg smaller.
5) Try the pants on your little one, right-side in. If they fit, then turn the pants inside-out again, and cut the excess off, about 1/4" from your seam.
6) You may also want to sew down your seams again with a zig-zag stitch (but only after you're sure they fit right!) to keep the edges from fraying.
7) Turn them right-side in again, and you're finished!