I am new to the game, and started as a wizard. Am only at level 7 yet. The mindset I have adopted is two-fold. First, there is gleefully watching charmed enemies butcher each other as you place your bets on which one gets nuked at the end.
10 spell points = 2 enemies dead.
Skills are specced to max hiding and move silently. It's not high enough to let me sneak past enemies reliably, but plenty high to let me approach, see, plan and start every fight on my terms.
Then there is burning things that can't be charmed, usually while they are webbed. Sometimes there is a slight burning of things that can't be charmed to get them in sight of things that can be charmed.
So lots of watching, and sometimes correcting an enemy health bar with an endless wand, if it outperforms the charmed mob by a wide enough margin.
Honestly, it was kind of boring that the strategy I used at level 1, still remains the safest and most efficient power wise at level 7, but spiders, undead, enemies and orange/red enemies do break up the monotony. Warforged enemies can't be charmed - suggestion works fine on them - but at double the cost, they are expensive.
Only downside is that cleric hirelings are a pain to manage - can't bring them anywhere near the fight as they will proceed to heal everything you charmed and then you are suddenly out of heals and half your enemies are at full health...
Now that I routinely loot basic damage wands (scorching ray and such), I often don't even need to use spell points to kill non-charmables that are webbed.