look at the entire board
if you are starting out you may want to play black for a while, allows you to play the defensive role until you can catch your opponent in a mistake.
Always look for your oponents next best move, watch all of their pieces, see where they are trying to go/where they can get you in a bind and block the move.
Try to look several moves ahead, dont attack/pressure a peice for no real reason, develop a strategy that will be to your advantage, also watch what your opponents best moves are in the situations that develop,