Experience
I workout a lot, a combination of running and weightlifting, and I was super frustrated with my underwear riding up so I tested a bunch of brands and styles and Tomboy X Iconic Briefs have become my go to style. They are the only brand and style I have found that lets me do my thing without having to worry about my underwear. I won't mention other brands, I have tried a few others that also don't ride up, but are much poorer quality and riddled with holes and falling apart, which my Tomboy X ones are not. I also tried their Tencel Bikini, and they're a better fit and style for more everyday wear, but not for working out. I like that they regularly introduce new prints and colors and just seem fun overall.