My question, how can you play a game knowing that you are going to draw? Do you have to defend? Exchange minor pieces? Mirror your opponent's move?

Generally playing for draw is difficult psychologically. It is tempting to avoid risk by exchanging pieces and simplifying the position; however, it easy to end up making concessions on every simplification and end up in a worse passive position. This is a very good recipe for a loss.

I don't think there is a good method of playing for a draw, but if all you need is a draw try to play normally. For example, if you are normally a sharp tactical player who plays the Sicilian go ahead and play that even if all you need is draw. Trying to play ultra safe chess that is not your strength in, say, Caro-Kann than you don't know will expose your weaker side and you are more likely to lose.

My question, how can you play a game knowing that you are going to draw? Do you have to defend? Exchange minor pieces? Mirror your opponent's move?

Generally playing for draw is difficult psychologically. It is tempting to avoid risk by exchanging pieces and simplifying the position; however, it easy to end up making concessions on every simplification and end up in a worse passive position. This is a very good recipe for a loss.

I don't think there is a good method of playing for a draw, but if all you need is a draw try to play normally. For example, if you are normally a sharp tactical player who plays the Sicilian go ahead and play that even if all you need is draw. Trying to play ultra safe chess that is not your strength in, say, Caro-Kann that you don't know will expose your weaker side and you are more likely to lose.