Give an extra perk to a cigarette smoker?

TOSSINTHEASHTRAY

Think of what you might do with a finished cigarette to keep things tidy.

This clue plays on the phrase "toss in" (meaning to add something extra) combined with "the ashtray," a place where smokers dispose of cigarettes. The word "perk" hints at "toss in" as a casual way to say "include," while "ashtray" directly ties to smoking. The answer merges these ideas into a single phrase, turning a literal action into a punny way to describe giving a smoker a little bonus.