I know. Just the word "scale" makes you think of mind numbing drills and hours of boring exercise. But I'm going to show you a way to learn any new scale AND actually be able to use it to improvise in just 15 minutes. No matter how simple or complex the scale is.
One of the best things about the guitar is moveable positions. That means you can learn a scale pattern in one position and be able to quickly change to any key you need just by changing the starting fret. Muscle memory and finger patterns become your best friend in learning a new scale.
This isn't to say that you shouldn't also be learning how the scale is constructed and what the exact notes are in each key. You need to know that too. But that can be the next step. This quickstart formula is just to get the scale under your fingers so you can begin using it. I'm also assuming here that you have a fretboard chart or some sort of notation that shows you what the notes for your new scale are.
This set of steps will help you learn the scale in one position. To learn other positions, simply repeat them at the new spot on the neck.
Here's the steps:
01. Using your notation to keep track of where you are, play the whole scale in both directions one time. Pay attention to the fingering pattern and shape on each string and look for patterns. In my head, a natural minor scale looks like this: 1-3-4,1-3-4,1-3,(shift) 1-2-4, (shift) 1-2-4,1-3-4.
02. Play the bottom 2 strings of the pattern, in both directions, 10 times.
03. Repeat step 2 using each pair of two strings, ie. 4 and 5, 3 and 4, 2 and 3, 1 and 2. Be sure to go both directions and keep your tempo slow and steady.
04. Next, play the scale with sets of 3 strings, ie. 4-5-6,3-4-5, etc. Go up and down, and do each 10 times like before.
05. At this point, you should be able to play the whole scale in both directions fairly easily. Play it with your eyes closed a couple times just to learn that you can trust your muscle memory. If you're still having some troubles with it, you can play groups of 4 strings like in steps 3 and 4.
Now we've got a scale, but we don't yet have music. Running a scale up and down won't earn you any platinum records. So let's break you out of that up-and-down pattern.
06. Start from the root note of the scale on the 6th string. Play ever other note (called 3rds). Go up and down in the scale this way and repeat 5 times. Then repeat this step starting on each note of the scale. Start on the 2nd, 3rd, 4th, etc.
07. Once again, beginning on the root on the 6th string, play skipping two notes in between each not you play. This would be playing in 4ths. Repeat that 5 times. Just like step 6, do that same pattern starting from each note in the scale.
08. Start from the root one more time and play this pattern: up two notes, down one note. Example: C-E-D-F-E-G, etc. When you descend, do the opposite: down two, up one. Repeat that 5 times.
Now you can play through the scale linearly as well as break things up into 3rds and 4ths. At this point we can start doing some improve with it.
09. Let's go back to the idea of using 2 strings at a time. Improvise on each pair of strings, concentrating on creating interesting rhythm ideas for between thirty seconds and one minute. If you have a backing track or something to play with, now's the time to get it out. See if you can cover 12-16 bars while improvising on just two strings of your scale.
10. Do the same with each pair of strings.
11. Repeat that same idea, but using groups of 3 strings. Keep in mind that everyone is using the same notes. So the real creative stuff comes in finding cool rhythms for those notes.
By now you will be completely confident with your new scale. To learn another scale or another position of the same scale, just repeat these steps. As with anything you learn on guitar, the key to keeping it locked in your memory is to use it consistently. Use your new scale every chance you get for the next two weeks and you'll have it locked into you mental scale repository.