I've found a couple of things can help out enormously.
1. Find a white 1H sword that can be used by a level 1 and enchant it with fiery. Find a white level 1 dagger or staff and enchant it with 30 spell damage. Now you have a weapon that will last quite a few levels and you can re-use it on other alts.
2. If you're a twinked out melee, your kill rate should be high enough that mobs in caves will respawn like mad.
3. If you're leveling a ret paladin, make sure to pick up
The Pacifier. your kill rate with that thing + SoC + fiery enchant will be absurd.
4. Spirit is all kinds of OP at low levels.