At some point in your pickleball journey, you will find yourself in a game where you're the best on the court. It's those times when you can work on some of the finer parts of the game.
See the ball hit your paddle - Sure. Very Obvious, but hugely overlooked. Don't just watch the ball hit your paddle - pay attention to where it hits on your paddle. Are you really hitting the sweet spot as often as you think?
Footwork - Get in position for every shot. Bend your knees, take the extra step. Too often players get lazy in 'easy' matches. Laziness and bad form = bad habits on the court. Dance like the pros: split-steps and quick shuffle-steps.
Talk: Mine, yours, just kidding, mine again - In crunch time, breaths get shallow and mouths get dry. Communication can dwindle when nerves obfuscate. So when the game doesn't matter, talk. Get in the habit of talking to your partner and create the habit now, so you can implement it later (when it matters).
Give up the middle - If your partner recognizes you as the better player, they'll likely want you to take middle balls. Encourage them to cover more of the court. Play the weak side and find ways to maximize your impact.
Think about how pro Collin Johns has become a lethal 'weak side' (right side if you're a righty) player.
Since you're not the focus this time, take time to analyze your opponent's tendencies, identify their 'tells,' and become a pickleball body language expert.