Watch the Video Lesson:
What I will show you in this tutorial is a shortcut. It’s a specific application (one of many possible applications) of the String Fragment System, that allows you to create diagonal fingerings for the Aeolian mode, on the fly.
We will use just these 3 string fragments instead of the 5 or 7 that are needed for complete vertical fingerings:

So let’s apply this to A Aeolian. You go to the 5th fret of the 6th string and place the 3-string SFS there.

Those of you that ave taken the SFS Modes crash course have seen ways to use these 3 string fragments already. We used them to jump all over the fretboard and play an octave of this mode. But now I want you to notice something. The 2nd note of SF3 is again an A. This means that if I slide my 1st finger to get there, instead of using finger 3, I am immediately ready to place the 3 string fragments again. So here they are. And one of the rules of SFS is that we shift one fret up when crossing between strings 3 and 2, so the system is slightly adjusted:

Now I can do the same there, because the same thing applies. The 2nd note of SF3 is again an A. So I can slide on SF3 on string 2, and start a new system on fret 10. This obviously has just 2 string fragments because we run out of strings. So here is what we get:

On the way back you slide your 1st finger backwards to go from SF1 into SF3 of the adjacent position. Again you need to remember the SFS shifting rule, so you should be careful to shift down one fret when crossing from string 2 to string 3 [example in video].
Obviously, if you start on the A string 4, or on string 2, you end up with the same diagonal fingering [examples in video]. But it’s nice to be able to jump to any A at any given moment, because this gives you new improvisation ideas. And you are not always going to play long runs to cover the whole diagonal fingerings, so it’s a good idea to see these A's as different options that allow you to play in different fretboard areas.
You can build a similar diagonal scale when you on string 5 [example in video]. And again, if we start on string 3 we actually get the same fingering [example in video]. But as we said it’s a good idea to treat these as separate options.
Alright, I will leave it up to you to figure out the details of how we construct this last one, and you should also check to see if you can find other places on the fretboard where you can do this. This kind of diagonal fingerings are great for long runs, and also make it easy to transfer the same ideas to higher registers, so that you can develop your solo through repetition and variation.
In the video I play a demo improvisation using the first one of these diagonal fingerings. Have fun practicing this yourself using the included backing track, and I hope to see you in the free SFS Modes Crash Course.