How can I signal to guys that I’m interested in them?

my gaydar is a bit wonky and I want to signal to men that I swing that way. I don't want to be obnoxious and wear a bunch of pride stickers and pins, but I can't think of a way to let it be known that I'm interested in boys without it feeling weird. The few times when I think I've found a fellow skittle member, it ends up being a straight man. The only gay people I easily attract are lesbians...which I don't know why that is.

I wonder if guys know when another guy is interested in them or not. since some of us can be clueless.