One habit that has helped me grow as a musician is learning to play songs that I know and like in all 12 keys.
Because it helps you hear the melody, makes it part of your musical vocabulary, and forges neurons in your brain that allow you to play by ear.
Anyway, you have to start somewhere. And I want to help anyone who is trying to get started playing by ear. In this video I walk you through the thought process of playing the Beatles' song, "8 Days a Week" in 12 keys.