Students will be spoilt for choice as far as straight maths is concerned. What might be more useful is if you can produce resources for the neglected papers in further maths - eg. Edexcel FP2 (if you did not study this at A-level you'll still recall a lot of it from first year linear algebra and group theory, assuming you're studying maths) & FS2, MEI extra pure (iirc), so on.
I tried to do this but lost interest when I stopped doing A-levels.