1. Practice does not make perfect. Perfect practice makes perfect.
If you continuously practice something incorrectly, that's how you will remember it for the rest of your life. Always strive for perfection when you're practicing. It is truly the only way to get better.
2. Someone will always be better than you, and someone will always be worse.
There was nothing more terrifying that playing right after someone who was great. But it was even worse if you performed right after someone who was horrible. Surround yourself with great people who continuously challenge you. If you ever feel like you are the best at something, chances are you're just becoming lazy.
3. Small bites finish the sandwich.
I always hated this expression, but usually because I was gorging myself on something delicious in huge mouthfuls. However, this is definitely true in business and in life. Whenever I find myself struggling with a daunting project, I find people or the time to break the project into its' simplest tasks. I typically do the easy stuff first, so I can spend the most time getting through the hard stuff. If you knock one or two easy items off your list, you will feel more accomplished and more motivated to get through the tough stuff.
4. Don't be afraid to challenge yourself.
Don't do something simply because it sounds easy. I watch many friends and colleagues maintain the status quo and complain about how little they're getting paid, or how bored they are. Don't be that person. Companies can always be improved, and when you feel overwhelmed with the challenge you gave yourself, see #3.
5. Seek advice of others.
If you don't know how to do something, no one is going to fault you for asking questions on how to achieve your goal. I learned that by listening to recordings of pieces I was to perform, I better understood the piece that just by sight reading it. Emulating something that works, but adding your own personal touch to it works.
6. Go for it.
Never do anything half-assed. Everyone can see right through it. Trust me. When you don't give it 110%, conductors, instructors, teachers, colleagues will remember it. You truly get to make a first impression every day, because every day is a new day.
7. You can't be everything to everyone.
I have small hands, so Rachmaninov and I do not get along. I had to learn the hard way that there was no way I could play most of his pieces. If you simply can't do it all, it's okay. Learning to say "no" is one of the most powerful tools a person can have in his or her arsenal.
What is a life lesson you learned early that's stuck with you?