I can't believe people have such a hard time playing on normal difficulty. So far I haven't wiped more than once on bosses I've encountered so far. What you guys need to do is watch some youtubes of someone playing and pick up some ideas.
My setup is a Primal Mage with Alistar as Tank, Lillian as melee rogue which is set to always attack Alistar's target. Finally I take either Morrigan or Wynn for healing. Here's my core tactic for dealing with everything that comes my way:
-Park party around a corner a reasonable distance away from enemies.
-Set party to hold position. Since my PC is a Primal mage, I make sure he's in the front of the party, see below.
-Take control of Tank.
-Body pull mobs, run back to your party.
-Let the majority of mobs turn the corner.
-Hit pause
*Set tank to attack strongest foe (Lillian doesn't need attention as she's set to attack the tank's target)
*Set Primal Mage to use Cone of Cold spanning as much enemies coming around the corner as possible.
-Unpause, let characters execute their moves, pause.
-Clean up adds by shattering them. My mage and Wynn do so (Stonefist)
-Put tank on adds that did not get frozen in place, DPS'em a bit.
-Issue Cone of Cold repeatedly on the boss mob or strongest mob while cleaning up adds.
-Finally have your party gank the boss by any means at your disposal. Minor healing required.
This works like a charm and most of the time Wynn is good enough to shatter the yellow mob, although I don't risk it on orange mobs due to higher resistance.
Crowdcontrolling is extremely important. Use Cone of Cold or Mind Blast for an AoE stun. You could say this particular tactic is cheap, however I take joy in avoiding usage of potions and other consumables. I just save them for the really tough fights.
Another extremely important thing to consider is party positioning. Friendly fire sucks? Nah, just position your party properly. If at the start of an encounter your party positioning sucks, simply select them all and make them all run back a good deal. This accomplishes two things:
-Getting the party bunched up.
-Getting mobs on only one side of the party contrary to being surrounded (VERY important for early level tanks as early on they are much more vulnerable from the back)
-Getting mobs lined up to mass Cone of Cold them, no party members in the way to prevent the use of AoE spells on the pack ahead. Use earthquake (Wynn) to make mobs trip as they run to you and stahl them so they stay longer in AoE you can lay down.
Learn the skills, learn what they do. Learn which skill affects other skills and have fun kicking the snot out of Darkspawn and other evils with a minimal use of consumables.
Oh did I say positioning is pretty much the most important aspect to surviving encounters?