zugzwang: dont let ur pieces hanging(without support) for long tym.
try to control the centre squares i.e. e4 ,d4,e5,d5, with pawns nd pieces
try to maintain atleast a pawn in d centre.
IMPORTANT Tip- once opening phase completes, try to break the centre in such a way dat ur most of pieces generate thier potential Energy..This is known as LIBERATING MOVE.