It is really hard to screw up. There are lots of ways to play, all perfectly valid on non-hardcore. A couple minor things that are sort of OP.
Have over 100% resistance to an element to be healed by it. So if you have 100+ fire resistance, and you get hit by your mages fireball, you get healed. this is PARTICULARLY handy for poison, and fire.
Wands are horribly over powered. If you dual wield them with dual wield 5 they take 3 ap to take two shots. They gain the bonus from the Bully talent. You can put a few points into the wand skill too if you like, but it is not necessary.
Lastly, avoid putting too many points into crafting on your real character. Choose one of the story characters you don't want to use, add them to your party, then send them packing. Whenever they rejoin your party they will auto level up, and you can give them crafting skills. It is worth it, the items made with level 5 crafting / smithing are some of the most powerful in the game. I did write a tool for the crafting,
www.irodemine.com/divinitycraft. Summons are very very powerful. Particularly early game. The easiest to obtain is the wolf from the first tier crafted earth wand, or the spider from the first tier warlock spells.
Again, you can't really screw it up. Look for synergy that you find fun.