This is kind of cheesey, but I when I am trading I like to think that I have a candle burning inside of myself. When I am trading well (i.e. following my system and rules) the flame is straight and calm, no matter the chaos of the market. When I am trading poorly (i.e. not following my system or rules), the flame flickers and moves as if the air around it is blowing about. Every jolt of the market moves the flame. If you trade poorly for long enough, the flame will go out and you can't trade any more.
If you think about it, it is easy to tell the state of the candle within yourself. If you are suffering while you trade, you are trading poorly and the candle flickers. If you are at peace and comfortable while trading, your candle is calm and you are trading well. As you can see, it has nothing to do with the state of the market or whether you are in profit or loss.
I have unfortunately let the indecisive action of the market the last couple of days disrupt my flame. Not for long. Wax on, wax off.