How do you secure thigh-high stockings on your thighs?

I came up with a cute pair of stockings for myself, leg warmers with no heel so you can slip a high heel through the hole and wear your summer shoes in fall. Anyway, I’d never knit thigh high socks before and have found that they definitely will not stay up even with a pretty tight rib, so what’s your favourite way to secure the top? If elastic, how do you sew it in? Or elastic thread in the rib? Please let me know. Thank you!