item buying: at the start of the game you see which hero you
are, see their heroes, then decide on an item build. if you're a
late gamer like razor or whatever, have the discipline to stay in
your lane, dont go for too much, just last hit last hit, heck care
the other lanes, just focus on staying in your lane and the
creeps.
set targets for when to get your desired items. if it's a pub,
please do not be one of those dicks who say "i am defending top
against the creeps, you all plz defend 2v5 k thanks" and use common
sense on when your team needs help.
personally, i find this is damn boring which is why i play ganker
for my team.. all i need is the imba bottle. and a hero like
bm.
EDIT: i see my post and i decide it's too damn long-winded. so i
summarise: see the situation and use your brain.