Instructions
Calculate the risks to losing one of your pieces. Determine what the short- and long-term advantages are to losing the piece you are about to sacrifice. Determine the value of the piece, and decide whether losing that particular piece is worth it to not have the piece anymore.
Consider your skill level. It's common for beginning chess players to sacrifice pawns, knights and bishops on a regular basis for simply taking out one of the opponent's more important pieces. You should take some time to weigh the options before deciding to do this. Once you have lost your pieces, you can't get them back unless you take a pawn to the other end of the board.
Sacrifice a lower-end chess piece if you can take out one of the higher pointed pieces quickly. If you can gain an immediate advantage in the game by sacrificing a pawn for your opponent's queen, do it. Take out your opponent's rooks and queen whenever possible, unless it will cost you one of your important pieces.
Sacrifice a chess piece if you can gain a valuable check or a checkmate out of the deal. One classic sacrifice has white sacrificing its bishop by capturing the pawn on h7 and putting the black king in check. The black king must then either take the bishop or lose a pawn without any advantage.