Keep your King Safe.
Everyone knows that the object of the game is to checkmate the opponent’s king. But sometimes a player thinks about his own plans so much that he forgets that his opponent is also king hunting!
It’s generally a good idea to place your king in a safe place by castling early in the game. Once you’ve castled, you should be very careful about advancing the pawns near your king. They are like bodyguards; the farther away they go, the easier it is for your opponent’s pieces to get close to your king. (For this reason, it’s often good to try to force your opponent to move the pawns near his king.)