I can't wear briefs for extended periods. It's the most uncomfortable thing like ever. Hurts, sweats, briefs offer NO space and my dick is claustrophic. Briefs have always been uncomfortable for more than an hour.
So I wear really baggy jeans usually that allow me to have on boxers or no underwear and, because of the size of the jeans, it won't be noticeably swinging.
If I have to wear tight pants, I still can't put it up, cus then there'd be an abnormal lookin lump held by me belt lol. So in tight pants, I just wear really tight boxers that allow me to let it go down the side of my leg. It isn't noticeable then unless I sit down, and only then if someone is looking between my legs which they shouldn't be doin lol.
Most times however I don't care who sees it swinging. It's a dick. I can't make it smaller, nor would I. So the people at my school, job, or wherever else have to deal with it, if they notice.
I always tell them "my face is up here, so what are you eyes doin down there anyway" lol.