Good bass playing, like anything really, is simple once you break it down. Play some notes from a scale in interesting patterns using good rhythm and technique and you have a bass line!
When you start to think like this, you come across all sorts of elements that you can include in your practice routine.
This video lesson is taken from my book Complete Fingerstyle Bass Technique. It comes with a free backing track and TAB/notation which you can find by scrolling down.
The example is in the key of C Major and the C Major Pentatonic scale is included in the PDF. I have a load of lessons that go into theory, scales, and improvisation. If you're unsure where to start looking for lessons, I recommend starting here.
Bass Backing Track & TAB/Notation
If you're interested in Complete Fingerstyle Bass Technique, it's available on PDF, Kindle, and paperback. Buy it here, and find out more here.
I also have a few more sample lessons from the book:
FAST Minor Pentatonic Bass Guitar Lick (Raking & Rolling Techniques)
Bass Guitar Plucking Exercise (Plus Fretting, Hand Shifts & Improvising)
The Thumb Pivot (Cool Hand Shifting Bass Technique!)