Years ago I would always wear suspenders (braces) with my dinner suit (tuxedo)...... I solved that problem by starting to wear my kilt to black tie functions. I wear a belt!
I can't stand the why a belt feels in comparison to braces. They just feel better and keep your pants where they are meant to be on you waist not down at your hips.
With casual wear, I wear a belt. In a suit, I wear braces. I wasn't sure I like them at first. However, once I got used to them, I really like them. It makes a suit feel much more comfortable. Of course, I don't like the clip on ones. You have to get the ones that require buttons inside your trouser's waist band.
I wear braces with my suits, with my sports slacks and with my jeans. They feel better than a belt. Only problem so far is how to wear them when wearing an aloha shirt and khakis!
Suspenders/braces do a better job of eliminating that vertical smile when wearing jeans/work pants. I generally wear them under my shirts and over my undershirts when wearing work/casual wear and am not in a situation that requires a tucked in shirt. When wearing dress pants and shirts I go with a belt.
I always wear a belt. My grandfather, on the other hand, wears both....and yes I mean at the same time. When anyone says something to him about it, he says that my grandma "works his *** off" and he doesn't have anything back there to help hold his pants up.
I mostly wear belts, but I always get my suit trousers taliored with the buttons in case I need to step my dress up a notch. It's nice to have the option.