Where one of the leads is goofy/weird, and the other lead is a cold/too cool for school vibe/popular kind of guy.
Orrr one of the leads is more on the introverted/shy quiet side while the other is an extrovert/crazy/too cool/or popular kind of guy. Like stated in the last one.
I also have found that I like when one of the characters have a crush on the lead but it turns out that the latter has liked him all this time, they just never knew.
I know.. kinda weird and specific, but I quite like these tropes. So if ya'll have anything similar to these let me know!
Few BLs I've seen already...
Star and Sky: Both
Theory of Love
Love in the Air
Cutie Pie
Pit Babe
Semantic Error
My Gear and Your Gown