My thought process when I'm on the court is always thinking about getting better, and thinking about how I'm playing. Thinking about it as a process, as the big picture and what I need to work on, instead of being close-minded and thinking, 'I'm so nervous and have to win this match, if I don't, it'll be the worst.'
One night I couldn't sleep at three in the morning and I thought, I'm going to color-coordinate my closet. And I did. There's a whole system. It goes from white to black and then all the colors in the middle. Then it goes by tank tops to T-shirts to long sleeves, and then it goes to the next color. Then it goes to sweaters the same way.
I have a specific routine before every match. I like to grip my rackets, because I feel that someone else won't do it how I like them. But the biggest thing is that I don't like to stress about my match all morning. Twenty minutes before, I'll sit down and think about the game plan and warm up. And then I just play.