I'm a jeans and t-shirt guy too. My team all pitched in and got matching polos with names on the front and designs on the back, which look pretty cool. I think next season we'll do the mock neck shirts. But everyone does their own thing with the pants. 4 out of 5, including me, wear jeans or shorts if the weather's nice. Our 230 avg anchor bowler only rolls in sweats, lol. At first he wasn't a fan of the polo shirts cause he'd rather wear a raggedy old shirt. But we wanted to look somewhat like a real team.
I've thought about trying slacks for the breathable, comfortable, lighter fit. But I can wear jeans and a t-shirt every day to work, so it makes me lazy to change before league, lol.
So only on serious tournaments with dress codes do I wear slacks. One of these days I'll try it during normal league.