Plan for success but have no expectations... A lot of trading emotion comes from expectation. Traders expect the next trade to be a winner, they expect this month to be profitable, they expect the USD to become bearish, etc, etc. Having no expectations can really help to reduce trading emotions. Obviously, you should still stick with a strategy and do all you can to BE success, just don't expect to succeed.
Success will come as you unemotionally stick with a strategy that gives you an edge. Success comes from trading your strategy with consistency, not be giving-up when expectations are not met.