Originally Posted by tcl
Sing what you will play before you play it.
Yep. Record what you sing, then listen back to it and learn to play that on your bass. It'll help you connect what you 'hear' to the fingerboard.
Also, learn to play melodies to lots of songs by ear. It's a great step that's easy and very often overlooked.
Pick one song and learn several different versions of it from different recordings. Pay close attention to how they interpret the song: the mood the singer captures, their unique phrasing, dynamics, etc. Don't overlook simple phrases as they contrast beautifully with complex ones.