It can be rather difficult to instill good gaming habits in others, even more so to reinforce or reward said habits without appearing to favor one Player over another. The imaginative denizens of 'Stuffer Shack' sought to correct this issue with the rather ingenious usage of a standard deck of cards. This "deck of boons" is quite straightforward, each card (2, King, etc.) has a specific, mostly positive in-game effect when deployed during the session at hand. Said benefits range from the practical and mundane (re-rolling an attack), to the intricately powerful (player fiat).
The real value in this system, however, lies in the acquisition of the card itself; a feat typically accomplished by those exhibiting traits that the dealer/Host may find desirable in an Player. Personally, I make it a point to reward any attendees with the habitual punctuality to show up on-time for the scheduled session with a draw from the deck. Though initially met with skepticism, a particularly impressive use of the 'Ace' card involving a blatant in-game reference to the movie 'Matrix' dramatically improved Player punctuality. Your requirements for such compensation, be they in-game or out, may vary.
Edit: I find myself thoroughly enjoying my blog's visual format. Particularly the font/color/size of the post titles; it caused me to read "The Deck of Many Boons" in a big, booming voice in my head. : P