Three limericks to memory and you can "tick off" all the sharp and flat scales within THE MAJOR SCALE.
Take the C major scale = C, D, E, F, G, A, B, C. Then using this limerick;
See, God, Destroy, All, Earth, By F#ire and C#haos. That is the order of the scales that that have sharps in them. For example:
C has no sharps or flats in it's makeup.
G has one sharp.
D has two, etc.
Now which sharp? For that I use this limerick;
Fat Cats Go Down Alleys Eating Birds.
The G scale has one sharp. What is the first sharp? F# for Fat.
D scale has two, the F# and the C#, for Fat Cats.
I cheat by just listing the notes in the scale, on my sheet music, for example; D, E, F, G, A, B, C. Then go to the Fat Cat limerick and add the sharp "mark". F# and C#. If you do not have some paper handy, use your fingers...
You can fill out the rest of the sharp scales by using those two limericks.
For the flat scales use; Farmer Brown Eats Apple Dumplins Gresely Cooked. Yes, you figure out how Farmer Brown gets all the flats. Hint; the F scale will have a Bb note. Take it from there.
Three limericks to memory and you have all the sharp and flat scales. Now finding the notes on your neck is the next step. For that I use the major scale box pattern, root note under the R.
Good luck.