(sorry I am just talking my face off with this topic but it is one of my favorites and I have spent so much time debating these topics with my brother and his BFF)
Do not be stingy with treasure and experience points. Now you don't want the heroes advancing faster than the campaign level, but there is no sense in being a miser. Heroes need allot of cash to properly adventure and explore. The players don't want to be stuck at the same power level for an inordinate amount of time. It is a game and you want them having fun so they come back. Now I almost never give them enough treasure to become wealthy, but I have given out enough treasures to make many of the heroes rich. Also I tend to err on the side of generous with EXP in games that use them as an advancement tool. If you take the long arduous route so that the heroes face every monster in the various power levels then you are not leaving anything for a future campaign. For games that use large amounts of EXP for levels I would advise increasing experience point awards by 50-75% that which is recommended in the book. For games that use skill based systems that award a few experience points per game session I recommend adding the following EXP awards to the wrap up and awards phase of game play:
1 Exp if the GM had fun
1 Exp for the Hero who faced the most danger
1 Exp for the hero of the player who takes game notes
1 Exp for the hero of the player who acts as hostess/moral officer for the game session {at my table this is the person who runs for pop, chips and sharp pencils ect...}
5 Exp for mission accomplished (not an award that happens every game for obvious reasons)
With higher experience point awards it increases the chance the player will get to see end game with their hero. The best characters are the ones we start from scratch and make it to the final battle so to speak. Those heroes are hard to attain with peoples real life schedules interfering with game time. Even with a generous Exp scheme it can take a very long time to see a character to end game.
With large sums of cash the heroes will be able to move armies and acquire rare and esoteric items for the wizard. One way I like to control the power level of the game and focus the money of the hero is a simple move like showing the warrior the best sword in the weapons store in the big city. It is a plus uber weapon of nasty doom and despair and it just happens to have a price tag of oh, my Goddess I will never afford this sword...But somewhere along the way you know it is time for that sword to become the warriors, he has saved every penny he could get for many levels but he is still short by allot. That is a good time to give a large treasure out at the end of a campaign. Suddenly the warrior has enough if he can get the other players to pitch in for him. Player plays the social cards on the other players and sure enough they do it and the warrior has the sword while becoming in hock to the other heroes. Of course you use the sword as a start point of a new campaign. When I pulled this one the sword was an epic item that was the property of a demi god NPC in my game. As long as the weapon sat on the shops shelves and no one claimed it as theirs for battle, the demi god was not aware it was on the mortal plane. Once the warrior started slaying with it, the demi god became aware his weapon was on the mortal realms and he started to send minions to get his sword back. Of course our warrior did not care to surrender his new shiny weapon of doom!
(I seem to have digressed.)
So it is said that if you know your enemies and know yourself, you can win a hundred battles without a single loss.
If you only know yourself, but not your opponent, you may win or may lose.
If you know neither yourself nor your enemy, you will always endanger yourself.
~Sun Tsu The art of War~