One thing I've done in most of my games is use what I call Drama Cards. Originally the idea came from a buddy who used Torg Cards but I simplified it because at the time I couldn't get my hands on any Torg Cards.
Here's the gist of it.
I use a standard deck of playing cards. Remove all the cards I don't need. Usually this is the 6-10 cards but this could vary to your tastes and the game system used with.
That leaves the face cards (I pull half of those too), the jokers and the 1-5 cards. At the beginning of a game session, I shuffle and the Players draw three cards each*. Cards are useful of that game session only, no hold overs to a later game, use em or lose em.
(*edited for clarity. Thanks Restless.)
The cards can never be used for your own character. They HAVE to be used for another PC OR NPC. Yes, you can help an NPC if you like, even an antagonist. (which has been done several times by my own group to curtail a PC being a prick)
RED Cards are for NON-COMBAT conflicts.
BLACK cards are for COMBAT conflicts.
The 1-5 Cards are a bonus to a roll. Any roll.
Face cards are an auto-success.
Joker is wild. Not only an auto-success, but a spectacular auto-success. This is how you cheat death and survive the vorpal blade somehow. Doesn't mean you're unscathed, but you somehow manage to survive a fall down Niagara Falls.
It's also important to narrate out the use of the cards/ successes for dramatic effect.
*Note: with the Drama cards in use I tend to be much more strict in my die-rolling, even rolling in front of people. They now have the tools to save themselves. I don't need to shelter them from a death by bad dice.