Serena  Williams comes determined to the court to make it happen. Confidence and believing that you can win are ingredients of the mindset of a champion. You have to work on developing that yourself. Work on improving your skills DAILY.

The mindset of a Winner

In 2015 Serena Williams already had 21 Grand Slam titles. She was only 1 title away from scoring 22nd one, which was only done by Steffi Graf. She made it happen by winning Wimbledon 2016. 
Never give up. If someone else is winning, you can do it too.

Never Giving Up

Serena Williams started playing tennis early on. Back in 2011, she had a major injury that caused her to plummet from being number 1 to 172. In 2013 she gained her rank back.
She decided to persist regardless of her injuries and losses.

Persistence

Last Saturday finished the Wimbledon Championship, where Serena Williams won her 22nd Grand Slam. This is the absolute record in her career. Not to mention that she and her older sister Venus Williams also won the Women Doubles in the final. (That game was absolutely EPIC).