Solo I just hunt under my level (Stuff thats still dark blue, maybe a couple light blue) and send in a DS'd pet. Fire if the stuff doesn't hit very hard (Fire's damage shield is better than the one you can cast), water otherwise. Sometimes one would go for me first, just sicced pet on any that didn't go for it first. /assist pet, burn down its target once it's at 50/60%, repeat. Damage shield usually keeps them pissed off enough to allow a heal or two as needed.
Doesn't always work out, but enough for when I can't find a group. Killing three light/dark blues is usually the same exp as killing one white/yellow, and more loot. Casters are usually a bad idea though :)