I generally practice 4 to 6 hours a day.
I practice scales, arpeggios, reading, learning new tunes, improvisation.
I choose one scale a week and focus on that. I'll run that scale as many octaves as I can (some scales are three octaves, some two), then I'll try different fingerings for that scale. Next I'll play the intervals (right now thirds) up the same scale, then down. I'll then practice the arpeggios, start on the I chord and go up, then descend on the ii chord, then ascend on the IV chord and continue until I arrive at the I chord one, two, or three octaves above where I started, then I descend. Of course this is all with the metronome set at moderate tempo.
Next I read (usually from the classical bass books I have). I'll choose and etude in the key I am working on and practice that. I use Franz Simandl's 30 etudes for the double bass and John Patitucci's 60 melodic etudes. I'll start at about 1/4=60 BPM then work it faster.
Then I either go to the real book and work on learning a standard or continue working on a standard I am already learning. I read through the melody, run through the changes just playing arpeggios, then melody again. Once I can play the tune that way, I practice walking basslines over the tune then some soloing. In this exercise I strive to have my walking lines make sense and clearly mark the harmony with out only playing 1, 3, 5, 7. In my soloing exercise goal is kind of the same, but I'm striving to also 1. quote the melody, 2. have coherence in my solo by connecting my ideas to each other, 3. just see what I can come up with.
I do this on both the double bass (upright) and the electric bass.