You'd like your pant legs to stay tucked down inside the top of a boot or bootie? Hi, I'm a newbie here who's never posted before, but felt I had to pass on this little trick that might solve your problem.
You'll need a length of that woven "buttonhole elastic" used in the waistband of maternity or children's clothes to adjust the size. It should be available from any fabric store or online sewing notions supplier. Also you'll need four of the flattest, thinnest buttons you can find, about a half inch in diameter - you'll see why flat and thin in a moment.
First, stitch a button on the inside of each side seam right near the bottom of your pant leg using a strong thread such as quilting thread - these buttons are going to get a lot of pull on them as you walk. Make sure you do this securely but without a lot of thread build-up. If your boot fits quite snugly, these buttons may get pressed up against your ankle bone which can be uncomfortable - that's why the thinner the button, the better. You should be able to stitch them to the side seam allowances so you can't see any evidence from the right side of your pants hem.
Then cut a length of the buttonhole elastic for each leg to button onto one button then down under your instep and up around to the other button. So you now have, in effect, a pair of "stirrup pants" but the "stirrups" are easily unbuttoned and removed when you take off your boots. I just tuck the elastic into a pocket or bag if I'm changing into indoor shoes in the winter.
You can do this with most pant length widths, although of course if there's a lot of fabric such as wide-legged pants it just gathers together in folds and might not fit inside the boot top attractively, if at all. It works best with skinnies up to bootcut widths. Also, depending on your pants fabric, it may crease too much to drape down smoothly over a shoe after being tucked inside a snug boot for an hour or so
I use this trick when I want my trousers or jeans to keep a nice smooth tucked line inside my knee boots instead of bagging up at the knees from the pull when I sit down, then stand up again. I would think it would work fine for ankle booties as well. Don't make the elastic length pull too tightly under your foot because it can get uncomfortable if you're walking a lot - just taut enough to stay under your instep. Hope this helps. Try it, and if it works for you, you may find yourself buying and stitching on buttons to almost every pair of pants you own!
