Better to prevent than to cure: lean the mixture during taxi. Lean it until the RPMs rise and then drop. Keep it there until you do the runup. Last check before entering the runway: set mixture full rich.
If you would forget to set it full rich and you would apply full power, then it should make it clear to you, otherwise you didn't lean enough.
The only times I have fouled plugs are when someone else flew my aircraft previously.