There are three ways to conceive a bass line, and they should all come together when playing.

Melodic : Find a melodic motif, repeat and change it through the chord changes or create a sequence that moves and changes around.

Rhythmic : Stating a certain rhythmic figure. For example playing quarter notes or a 2-feel rhythm without any “embellishment”. It’s always dictated by what kind of music you are playing because every rhythmic figure is allowed as long as it matches with the general vibe of the music and its style.

Harmonic : Finding alternate ways to go from point A to point B is really fun so if you know the changes of a tune really well you can find different harmonic solutions. It is also very powerful to just play the most simple movements and see what you can do with that, How creative can you be just sticking with what is already there? I find that bass players play some substitution chords just because they know them but not because they mean them.

Thanks for reading,

G.C.