In the game of chess it is very possible to beat yourself and to block your pieces in with poor planned moves. While this is a simple concept that may seem obvious, many players will make this error. For example, moving your bishop in front of your pawn in the very early stages of the game will generally result in retreating that bishop so that the pawn can be freed. This is a waste of precious moves. Any move that has no purpose or strategy is a bad move. You only have so many opportunities to move pieces throughout the game so it is important to make each move count and for each move to be a part of your overall strategy. Waiting for you opponent to make the first mistake is your first mistake.
Another blocking error is when you have two pawns next to each other and you use one pawn to take a piece that is in front of the other pawn. Now you end up with one pawn directly in front of the other. The opens a file (vertical spaces) on the board and seriously weakens both of those two pawns. Your level of vulnerability to attack has just increased dramatically. In addition to this, the pawn that is the furthest forward is most likely undefended. This has created a sort of traffic jam for your pieces on the board and will haunt you as the game progresses. An experienced opponent will exploit this open file that you have created.
Always try to be thinking ahead as to what your next few moves should be. Thinking ahead will help keep you from blocking yourself in and from making the avoidable careless mistakes.