There’s no room for compassion at the poker table. Opponents are opponents; it doesn’t matter if outside of the table they are your friends. Therefore they must be treated according to what they are. Bear in mind that if you show any sign of weakness, they will exploit just as you are planning to do to them.
The best thing I can advice you to do is to become as emotionally strong as you can be, polish your strengths, mask your weaknesses and make the most of any mistake that others make.
Your play must be firm and objective, just as your attitude as you make every move in every hand. However, this doesn’t mean that you have to play with an angry face. Try to keep positive and simply make sure that you put into practice all that you know. You can practice this and many other “poker faces” while playing free poker games at your favourite poker room.