Kill off enemy creep? As in creep tumours? I'm still trying to find the best items, but, so far, I find that the weapon and speed items you can buy from the prism/queen are the best to start. Then I aim for the neosteel armor, maybe anaerobic regeneration, along with some weapons one such as the rail gun and not sure what the other is called, has a flame on it. I think once you figured out your preferred character and best weapons, it'll make the game much easier
creep=endlessly spawning units that are crashing into each other. figuring out figuring out the item situation really helps a lot....
my keyboard purchases have had the primary focus of improving my apm :b and honestly? the blacks really didn't feel right for rts type play imo.