Here are ten tips that I guarantee will help you master the bass guitar fretboard. This is an area of bass playing worth focusing on as being able to fly around the neck without thinking about things vastly improves your creativity.
This lesson follows on from 10 Ultimate Groove/Feel/Timing Tips For Bass Players and 10 Music Theory Tips For Bass Players.
1. Know 5 octave patterns
Octaves are used a lot in bass lines plus they bookend scales, triads, arpeggios, and chords so you can play a lot of music in between them. Plus, once you know the notes of an octave, you can quickly figure out the surrounding notes.

5 Octave Patterns For Bass Players
2. Memorise 3 positions for every scale
This opens up most of the neck and breaks you out of tried and tested patterns you come to rely on. This lesson goes into it much more: Incredible Way To Learn The Bass Fretboard!
3. Play a scale up one string
Another way to break out of old habits. Sliding across one string creates some interesting sounding phrases too plus you get to learn the formula of the scale and the sounds of the intervals.
4. Know every note in all its locations
Crucial for reading music, playing songs in different keys and your general understanding of music.
How To Find Any Note On The Bass Guitar.
5. Familiarise yourself with the piano keyboard
Notes on the bass seem so confusing until you realise that they come from the piano keyboard which is a completely different design to a bass fretboard!

6. Play patterns in different locations
This is an easy one. Just take patterns you already know and apply them to the same root note but in different locations.
7. Connect intervals to sounds
Every interval has a characteristic sound as well as a specific pattern on the bass. Link the two and you're strengthening your ear whilst memorising the fretboard.

8. Learn some theory
Once you know a few arpeggios, chords, and triads you can work out the tiny differences between them and link those to changes in patterns on the bass. Not only can you come up with creative lines that way, you get to see the commonalities between chord tones.
I have loads of theory lessons here.
9. Play on two strings
This is another way of breaking you out of the familiar. Take any scale you know and play it on just two strings. You'll be playing three note per string patterns which will allow you to do so much.
10. Map out a key and its chords
When you link chords to songs you find out that the same progressions are used ALL the time. This is a huge breakthrough moment that makes learning songs easy and playing songs on the fly a doddle.
This is the lesson for you if you want to learn how to do that.