Once upon a time, my electric guitar teacher learned me the scales on one simple rule: 3 notes on every string - no open strings.
You can even found these out yourself. These few "modes" that are created are repeatable, and you can easily later improvise on them, or play exercises on like: 1,2,3, 2,3,4, 3,4,5 ... etc or 1234, 2345, 3456 ... etc, up and down the fretboard. Very good basis!
hope you find this helpful !