be patient. after you make a descision on a move dont touch the chess piece. take a second look at what your opponent will do next. this will help a lot. dont worry about the clock if you have 30 minutes on the clock in an endgame and your opponent has 5 minutes left on his clock with a winning endgame what good does time do you. dont ask for their rating until after the game. this way you dont take the game too lightly and if its a higher rated player do not expect to take a loss from it. good luck.