Role-players want rewards for accomplishing things in the games they play. Game-masters have to maintain a balance in giving away character loot that won't make the party overpowered. The loot spiral can get out of control quickly as better equipped challenges lead to better loot. Reward tokens were the answer for me. Each token is a one use effect that may be used at any time. This allow DM's to increase challenge without needing to increasing loot and still give players rewards for doing cool stuff.
My house rules (Feel free to create your own)