The best thing I ever did for my jazz playing was to get Gary Willis' book "Fingerboard Harmony for Bass".
The gist of it goes as such(but get the book too, if you can)....
First, I'll assume you play a 4 string so the examples I give will be numbered/noted that way.
1. Starting on the low F note (1st fret low E), play a Dmin7 arpeggio(D-F-A-C) all the way across the neck using only fretted notes and no open strings, and then back down. STAY IN ONE POSITION(don't move up the neck). The highest note you will play is C (5th fret G string).
2. MEMORIZE the SHAPE. Do this however you need to. Take it in sections, and memorize triangles or squares, whatever you need to REMEMBER the shape.
3. Then play a G7(G-B-D-C) arpeggio starting on the same low F, across the neck(only fretted notes) and then back down. The highest note you will play here is the B(4th fret G string). MEMORIZE the SHAPE.
Once you are comfortable with the shapes, and can play them at a good speed....
4. Play a Dmin7 arp(off of the low F) to the high C note. SWITCH chords, and play a G7 going back down(starting on the high C) to the low F.
5. Once that's comfy, switch the order and play the G7 UP, and Dmin7 DOWN.
Here's where things get cool...
6. Start on the low F note. Play FOUR notes of the Dmin7 arp going up. Then SWITCH to the G7 arp, and continue going UP. You will hit the high B note on the 3rd note. Start going back down by hitting the G note. Then switch back to 4 notes of the Dmin7. Continue to alternate the Dmin7 & G7 arpeggios, 4 notes at a time, going as high AND low as you can before changing directions.
You will notice that certain LOOPS start to show up, where you will repeat the same shape patterns. In that case, start the exercise on the A note(5th fret low E) and go up, followed by the C(3rd fr A), and then the D(5th fr A).
7. Once THAT is feeling pretty good, then you will substitute every 4th chord tone(Dm7 OR G7), with a PASSING tone. This will be a note that is NOT part of the Dmin7 OR G7, but LEADS YOU into the NEXT chord tone of the chord that you are changing to.
EXAMPLE:
Chord: Dmin7 pass G7 pass Dm7 pass G7 .....
Notes: F - A - C - C# - D - F - G - Ab - A - C - A - G# - G - F - D...
Three things to note here...
ONE- When you play these chords "in position" you should ALWAYS play the low G note with your middle finger, which also means anything on the 5th fret is played by your pinky. ust play ONE FINGER PER FRET.
TWO- When you play the Ab or the G# you should always PULL any notes outside of the "one finger per fret" rule back into the 4 fret area. When you play the Ab note going UP, reach with your first finger to the 1st fret on the G string and then PULL it back onto the A note. Like wise, when you go down to the G note from the G#, reach with your 4 finger to the 6th fret on the D string, and pull the G# back to the G note on the 5th fret.
THREE- Anytime that run into a situation where the next chord's chord tone is more than a whole tone away (G7's D going UP to Dm7's F) then your note choice HAS to come from the key of C. Dm7 and G7 are derived from the key of C. You passing tone in this case would be E.
8. Now that running passing tones on the fourth chord tone is comfortable, start inserting passing tones on the second AND fourth chord tones. Continue to go up and down across the neck as far as you can before changing directions. Here's an example of the notes(and sounds) that you are looking for when you substitute passing tones on the 2nd and 4th chord tones.
Chord: D p D p G p G p D p D p G p G p D.....
Notes: F - G - A - Bb - B - C - D - E - F - G - A - A# - B - A - G - F# - F.....
If there is any way that you can play along with the Dmin7 & G7 chords while you do this, it will make for a substantially shorter assimilation time. Get someone with a piano or sequencer to record 5 minutes of four counts of Dm7 then G7 then Dm7, and so on. Get them to do it at a speed that you will be comfortable with.
If there was ONE thing that doing this series of exercises did for me, it opened my ears to note choices that I had never considered. I found myself instinctively throwing passing tones into places that I previously never would have imagined. And I didn't even have to think about it. They just came out. I also got to see the fretboard in a way I never had before. I understood it, and struggled WAY less with finding different note choices when I started repeating what I'd done before.
I hope this helps, and please let me know if you have any questions. Make sure you understand all the steps previous before you move on to the next.
This will get you used to walking, and NOT always playing off of the root as well.
Good luck.