get tattoos, grow your hair long, become a drug addict, worship satan
... then practice minor and pentatonic scales in all keys and dropped d tuning if all you have is a 4 string. learn to play along with your favorite bands recordings to develop your ear. Get a drum machine and play along at fast tempos with aggresive metal style beats.
If you prefer to be a well rounded musician who can play anything, study with a
qualified music teacher who will teach music, not licks and tablature.
The better bass players are musically educated. i.e. Dave LaRue, Stu Hamm, John Myung, etc.
