That's the best tip of all. Ask yourself this question: "Can I walk through all the vimtutor examples without thinking too much?" If you can't, there is probably stuff in there you should learn. Make sure you know what an operator is, and what insert mode does. Listen to vimtutor when it tells you to learn by doing, not by trying to memorize everything in the tutorial. I learned by doing vimtutor over and over again until I could complete it without referring to help. If I forgot commands, I'd start over completely at the beginning and progress as far as I could until I had to start over to review. Do this a dozen times or so and soon you'll have basic facility.

Also, use vim for everything, not just code. Use it for email, writing projects, file management, and explore what else it can do for you.