XENOMORPH
When ur an Alien, please no tail spams, and no ganging on others unless they are teaming on u, but no 100 to 1 please, ok? And go all out and E kill all u want, but dont, i repeat DONT stealth kill (back grab) unless it really IS a STEALTH kill, as in you walk up behind them without them noticing and grab them before they notice that you are even there, but, if u get the chance to forward kill, as in you knock them down, or make them flinch, their already dead anyways :\
NEW RULE FOR ALIENS: Dont circle grab!! As in circling around someone untill you can get an E grab in, DONT do it, its cheap

PREDATOR
Dont use ranged weapons on aliens unless your outnumbered, as in u vs 2 or more, but otherwise, dont shoot at them, its not nice, but go ahead and use combistick, as long as you throw just 1 for each target, thats actually a challenge to use, DONT SPAM ANYTHING, and again dont heavy spam (oh and BTW, only use like 2 mines at a time)

MARINE
Comeon! You gotta try going off on ur own, marines are pretty cheap, hidin in huge groups with a buncha smartguns, I mean really??? Dont stay in groups of more than 3, its just kinda cheap to all stay huddled together in a hall or some corner.