Just a quickie today.
The idea of "cantrips" is a very popular one. Minor spells to do more "wizard" type of stuff during the game, and reward creative thinking.
A very simple solution I saw proposed once is to simply let the player invent little effects based on spells already in memory. In other words, the wizard is "letting out" a little of the magical energies.
The trick must be thematically similar to the spell in question, and be very minor in effect. For example, a memorized fireball spell might let you heat up a bowl of food or set fire to already dry wood, while a memorized sleep spell could lull an already sleepy guard dog to a snooze.
Let the players be creative. If a player suggests something that is a bit outside the norm, give him a 1 in 6 chance of it working.
Do you use cantrips? Post a comment!