One way to learn scales is to use 18 note patterns for all 7 modes over 6 strings and then shift vertically into whatever key you like. That involves learning 126 finger positions and you now can play a single fingering for each mode.

My system involves learning a 21 note pattern and adjusting one half step around the major 3rd between the 4th and 5th strings. This gives me 3 fingering options for each mode, so I get 3 times the options for 6 times less memorization.

The system can (and should) be simplified by the user further, since the 21 note pattern can be constructed of 3 patterns with 3 notes each. This means you only need to memorize 3 patterns (x, y, and z) with 3 notes and learn the order of the patterns (x,x,x,y,y,z,z) to give all 378 notes in the 3 fingering options for all 7 modes.