1) When arguing, do not change the subject. It is ok to argue multiple points in the same arguement at the same time, but do not chage the subject entirely.
2) This sort of goes with 1, but do not switch to a different argument. Just no.
3) When you are losing, don't do stupid stuff to postpone the loss.
4) If you win, do not brag or whatever about it for a long time.