You could try to learn a song/solo that uses the scale / key you are interested in - possibly using several positions on the fretboard. Or you can try to write some simple solos/exercises that are based around a pattern that you want to learn.
Just learning the shapes without attaching actual music to them is not very useful… ask me how I know 
Try: Scale in one shape, all keys (i.e. all 6th string roots). That helps you learn the shape independently of any particular notes or key.
One key, scale in all positions (i.e. over the whole neck/starting from each degree). That helps you get fluent over the whole instrument.
One position, one scale, all keys (i.e. staying in exactly the same part of the neck) This helps you actually know the notes in each scale.
Sorry I’ve been a bit loose between scale/mode/shape there but I hope that makes sense.
Quickly switching between keys will teach you more than trying to drill one key til it’s “perfect”, but it might feel worse while you’re doing it.
Go round the cycle of fifths rather than chromatically when you’re changing keys. In the CFBbEbAbDb direction because we’re all cool kids here.
I see them as shapes, and I played around with 3 note and 6 note shapes for modes of the major scale. I used four and 6 note patterns for pentatonic major, minor, and their modes. Eventually I used the 3 note and six note thing for the harmonic minor and other variations on major and minor.
One thing I did was practice ascending or descending, instead of up and down, or down and up. The muscle memory is different and I guess the aural memory is different too. Sing them! I wish I did more of that.
For a new scale I’ll try to learn it in two positions, with the root on the 6th and 5th strings. Then play it over a chord to get the sound of it in my head. After I’ve got the sound and fingerings memorized I’ll learn a little connector bit to so I can move between the two positions. That takes care of most of the fretboard. If I end up using the scale a lot I’ll add in other positions bit by bit.
I find the sooner I start making music with something, the easier it’ll stick in my head. So I’ll learn a scale and try to write a melody or phrase or riff with that scale/shape right away.
@davetheguitarplayer just shared this little lesson he learned years ago from one of his teachers on how to learn scales:
I think it complements each of the approach each one of you guys have shared over here.
A recommended read to everyone!
Totally agree! No music, no learning.
Practical, why bother learning 7 shapes of a scale you don’t plan to use quite a lot? Thanks for sharing your thoughts.
Yes, singing is an essential part of playing, I’ve heard that the “ears” remember what the hands forget
Interesting approach, I’ll put it on practice during my next study season. Thanks a lot.
I’ve gone away from just blasting up and down scale Shapes (which never really sounds good in a solo imo) and instead have taken an approach that Jens Larsen recommends. It’s much more about playing the structures of that scale: Triads, Spread Triads, Arpeggios, 3 Note Quartal Harmony, Drop 2 Arpeggios (usually horizontally along the neck), and Shell Voicings. This approach really helps you to theoretically understand the different harmony of the scale, and allows you to “think” in that key; it also really helps if you say the notes as you play each one or even just the name of the triad/arpeggio. For the Triads and Arpeggios play them in all Inversions (Root, 1st, 2nd, 3rd).
This of course is a lot of 1NPS Alt Picking (Crosspicking).
I’ll do these in position as well as horizontally along the neck on string sets. For Triads I’ll also add in some different exercises
1. Approach from a half step below
2. Approach from a Diatonic Note Above
3. Enclosure- 1+2 or 2+1
4. 315 pattern (start on 3rd, go down to root, up to 5th)
5. 513 pattern (same as #4)
After this it’s about using all these different harmonic concepts and applying them to lines to play over the changes. It really helps to sit down and write out these lines by trying to create multiple lines with 1 concept (something like playing the arpeggio from the 3rd or the 5th) on paper.
hahaha no question is needed 
Counter suggestion - don’t!
When I interviewed Albert Lee, who I think is a great improviser, he couldn’t play a scale. Not in a straight line. I asked him to, and he played a slinky little phrase that had a few sequential notes, then a slide, and some legato. So I said, “I mean, scale, you know.” And he did the same thing again, just a different variation on it.
Point being, for most people, eventually you’re going to end up with some kind of vocabulary of cool phrases that are based on a scale tones, obviously, but are more phrases than scales themselves. Why not start with those phrases? It’s way easier to memorize a cool phrase than a thousand notes in a big shape you might never play. And phrases are easy to modify over time, even if by accident, to create a real-world vocabulary.
Years ago I bought Mick Goodrick’s “Advancing Guitarist,” and in it he makes general suggestions about “how to practice.” In addition to many of the things people are saying in this thread, Goodrick also says, “Well, there are seven modes in a scale, and seven days in a week…” and “there are 12 keys and 12 months in a year…” So I committed myself to doing a lot of what he said to do, and at the “end” of that I had “memorized” some things, but, like many people are saying here, hadn’t really learned them, and never used them in a musical situation. So whatever approach one takes, maybe differentiating “memorizing” or “rote” from “learning” would be helpful. I actually just checked out the definition of “learn,” and the current English word has a connection to the Old English word for “footprint” and the Latin words for “furrow” and “track.” Now those are some powerful images for what we are striving to do here!
I use what I lovingly call “brute force”.
So, let’s say I want to learn Altered in G, 3rd position. I will drill that for 20-45 minutes, and just that, a day until I get it.
Included in that time is me naming the notes and intervals. It’s not exactly fun, but I make it somewhat enjoyable by adding humor to it and singing along. It’s the only way I can learn, or, rather, only way I’ve learned to learn haha
Interesting topic. I remember reading an interview with Dave Fiuczynski and he said if he was to start all over he wouldn’t learn scales! He would concentrate on arpeggios and melodic fragments. Having said that Dave teaches at Berkeley so his scale knowledge is probably amazing. It was just interesting to hear a world class musician saying he wouldn’t bother with scales.
I think this is quite common amongst people who are masters of a genre rather than the…“look at me, I can improvise over any chord” (but just not very well) types.
Here’s jazz guitarist Martin Taylor, who’s right up there in terms of ear and improvisational ability and who played with Stephane Grappelli for 11 years, on the subject…
Totally. I don’t even know if “masters of a genre” captures it. I would suggest that players who are more melody-focused tend to think and play this way. If we find ourselves repeatedly describing someone as “musical” it’s probably because they have this phrasal way of thinking. You can start out super mathy with scales and patterns, but at some point it has to get melodic if you want to sound “musical”. Again, super vague this term “musical”, but I think that’s what most people really mean when they say that.
And again, one really fast way to be “musical” is to start out with phrases and melodies, and not with scales at all. It’s clear from this awesome clip that Martin knows where all the scale tones are. But it sounds he got there by filling in the gaps around the phrase, rather than starting out with all the scale notes and picking the phrases out of it.
Alright guys, I’ve been experimenting a bit.
I’ve been classical guitarist for several years now, lots of technical workouts, lots of etudes and complex pieces, but never deep analysis on stuff like harmony or improvisation until now (I’ve been playing for at least 11 years, hehe), the only scales I learned was the “Segovia Scales”, and it helped me to learn the notes on the fretboard.
Based on all the commentaries and points of view, I decided to try both approaches.
I took a simple progression: Cm9 - G7#5
I tried:
1. Learning a couple of patterns: It was hard to memorize them, I had to use sheer will and repetition in order to achieve my objective (get two “superlocrian patterns” under my fingers, I already know some pentatonic licks and shapes).
2. Learning only melodic segments as a baby learn words when first learning to speak: This was super fun and I got 3 licks under my fingers that go from Cm9 to G7#5 real fast, it took me to days of repetition to ingrain them in my playing.
In my today’s practice session, when I hit the play button to reproduce the Cm9 - G7#5 backingtrack, I start playing the licks right away, and it was magical. Music flowed out of my guitar and for a moment I couldn’t believe what I was hearing.
But the experimenting did not end here, I related both licks with two new superlocrian patterns and I got them under my fingers right away. It was a similar sensation to that crazy moment when I started playing Yngwie diminished arpeggios right after watching a Cracking the Code episode.
Right now, I think learning phrases is the way to go if you want to be an improviser, scalar shapes, we could use them as little capsules to organize the phrases and gain certain knowledge of the fretboard? I think yes.
Tonight I’ll go to bed knowing that I finally found a solution to this puzzle that caused me many nightmares.
I memorized scales by ear, over a chord. Get a “freeze” pedal and play the chord, and then play the scale over it, until you memorize it “by ear.”