so i've just got a squier showmaster, i dont know much about customising, but are there any recommended customisations i could make to it to make it sound better? i mainly play metal/rock. sorry if this has been asked before.

Get the thing setup properly first. This includes action, intonation, truss rod adjustment, pickup height adjustment. Then if you still don't like it, come back and post here.
^You could do that.

You could also get new pickups for it.
"Breathe, breathe in the air
Don't be afraid to care"

Fender Strat/Tokai LS80>few pedals>Orange Rocker 30
depends if its a plywood ifs its an alder maybe you could do with some new pups. A re-spray could be easy just check out my threads on how i did it (read sig)