Learn to be a pro sight reader. Sight read classical. Working on that, but I'm terrible at it.
Start/join a jam/group with higher level musicians. I'm jamming with whoever I can find, there aren't many high-level musicians in my entourage.
Notate difficult bass recordings. Check!
Learn piano/synthesizer bass. Check!
Play melodies on your bass. Check!
Learn music theory. In progress!
Learn to sight sing. In progress
Learn to play bass lines to chords. Check!
Visit the DB side of Talk Bass. Learn jazz/upright bass. Learned the DB, I own one!
Learn piano. I try, but I'm a godawful keyboardist.
Take voice lessons. Sing harmony in an a Capella group. I'll do it when I have the money.
You can easily add 2-4 hours a day to your practice schedule and come up with a 10 year plan. 4 added hours a day over 10 years is over 14,000 hours. I'm a student, I'm doing what I can.
Oh yeah, and also record yourself on a regular basis and save recordings for critical analysis by you and trusted others. See if others agree on how good you really are. Every time I play a gig I record it.