I teach a beginner band program. I'm a brass player myself, although I can play most of the band instruments with a fair degree of success. When beginner clarinet players start to learn B/C/C#, or the lower end equivalents E/F/F#, they have a hard time remembering which keys are for which notes. Do any clarinet experts have any clever mnemonics to share that might aid young players?
Then they go L-R-L-R for (lower octave) E-F-F#-G#.
Once pupils have learned that, then you can add the alternative keys (with the optional LH G# key if they have it):
and play the same notes E-F-F#(-G#) as R-L-R(-L)