The pair of jeans below is a boot cut jean, that I normally wear with heels. It is a light weight jean that is loose fitting.
Pinch the middle of the jean in the front and fold over. The bigger the pinch, the slimmer the bottom will be.
Now, fold up. I normally fold mine up 3 times. Puts them a couple of inches above my ankle, and I wear with heels. Or sometimes with flats, like Audrey Hepburn.