Set your autopause to "when enemy sighted." It's much easier to wake up only *one* of them this way.
Missile: Run'n'gun should work. Shoot, run, count out about 10-12 seconds, stop to shoot again. Rinse, repeat. Pause as needed.
Melee: Let the monster come to you, so you don't accidentally wake up his ugly twin. When he gets sufficiently close, pause and center an attack on him. (Note: Have archers begin assault before he gets close, so he's weakened when he gets to the meleers.)
Magic: Color Spray and Sleep can be helpful here, assuming the monster doesn't successfully save vs spell. Blindness can help weaken his attack rolls. Grease can slow him down, to allow your archers to get in some hits. And, of course, pound him with Magic Missiles/Chromatic Orbs as needed. You can always head back to the Jovial Juggler for a nap.
Who's in your party, btw? Imoen, Xzar, Montaron, Garrick, Kagain, Khalid, Jaheira, Kivan, Ajantis? Those are the most likely for a young party... And what class are you playing? (What weapon proficiencies, too?)
As with D1, it's easier to tailor-make tips if one knows what you have to work with.
[o: *LEMMING* :o]