Excellence is doing an activity as well as you can do it while learning how to do it better the next time.
Excellence requires focused attention and effort. Let go of doing and thinking about other things as much as you can. Start today. What is one thing you can stop doing or stop thinking about? Let go of that one thing and pour that time and energy into focusing on the one thing you want to be excellent at.
If you do that every day, you will steadily grow in excellence in the areas you want to focus on. Letting go of unnecessary activities and thoughts allows you to concentrate that time and energy on the things you really want to be excellent at.