I've started an exercise that (I believe) has helped my intonation and bowing.
Using Sibelius (notation program) I wrote out in E, an arpeggio (E G# B E G#E, in whole notes, then descending, then the E diatonic scale (two octaves) then descending, then broken arpeggios (E G#, F# A, G# B, A C#, B D#, C# E, D# F#, E.) Then descending.
Then the same exercise, from F, F# and so on, in all the keys.
I then play back the exercise with the sampled bass, and also added an organ sound doubling, and an octave higher.
Starting a mm60, and after some days, increasing the speed, always concentrating on intonation, but the bow sound necessarily important.