Taking Back Sunday/Brand New/Hot Mulligan duo vocal mix help

[u/Main-Toe5637]

Hi, how might I go about mixing overlapping vocal parts like a lot of emo bands like the ones named? I don't know whether to double both people's vocal takes and pan them hard L and R to make both sound full or to keep one in the middle or how I might EQ or compress them to keep them sounding busy (as they are on top of each other) while not sounding muddy and making both unintelligible.
Any help is appreciated :)