Gary Burton, in his Coursera/Berklee Improv course presents ten scales in decreasing order of "brightness." These ten scales provide a sufficient foundation for improvising over most of the chords in most of the tunes ever written. For my guitar playing friends, I've created tab to show how these scales can be played, with roots on strings 3, 4, 5, and 6.
In places where four notes are played on a single string, I recommend that you learn first by sliding between two adjacent notes. Experiment with different pairs of notes and choose the slide that feels most natural and efficient to you.
Bear in mind that the patterns I've tabbed out here present only one of many possible fingerings. Learn these and others along the way or in sequence. Learn them in different styles, different rhythms, and with different accents. The more ways you can play them, automatically and anyplace on the neck, the better able you'll be to improvise on demand and on time!
That said, don't focus on these to the exclusion of leaning and practicing tunes or the other ways of practicing that you've found to be effective.Ten Scales, roots on strings 6 & 4Ten Scales, roots on strings 5 & 3