These are just some tips that I've come across while playing as a Life wizard.
Tip 1: When your in a group, heal your teamates before you attack even if you could kill a monster. Why? Because if your teamates are on low health, when they get killed. You end up spending more pips to attack and then heal by then just healing. In short: It helps make the battle shorter, and easier.
Tip 2: Get a high Power-Pip chance, this may go for all schools but Life is almost a must. Having to wait a couple of rounds before you can heal/attack puts you at a BIG disadvantage. Esspecially past Marleybone where enimies are going to take some strategy to take down.
Tip 3: Strenght is in numbers, the more Wizards you have fighting in a battle, the easier it is for all the wizards. Focus on a single target and take the monsters out 1 by 1. If you know a teamate is going to kill an enemy, put on a shield or a buff for youself so you can hit the next monster really hard.