You are a man = no hips > elastic sucks
OP is a woman = hips > elastic rocks
Hmm, I'd never thought of it that way.
I have some pants that have three features that help them stay on better than the standard all cotton variety.
- Elastic waistband. I like this as it means the belt/tie is not so essential.
- The belt/tie is of round cotton rather than the flat material that's in the normal pants. There have been times where the flat material got stuck and I could not get the tie to slide enough to get the pants off.
- They are two sizes smaller making for a snug fit.
I found them at a local Chinese martial arts outlet (they have many sharp pointy things we don't see in Aikido or Karate). I suspect if I phoned around to the various dojo, dojang, and other schools I'd find someone that carries this style and are available for sale.
I've seen gi tops with extra ties to keep them from flapping or sliding open. Many women use sports bras with some of these looking enough like outerwear that the wearers can change tops on the mat before/after class without feeling feeling self-conscious. Most of the women wear a shirt. I recommend shirts for the guys too as it helps in soaking up sweat. While people talk about Velcro I've never noticed anyone that uses it.