while leveling affliction I just try to multi dot and drain. On single target get your dots on the target and haunt, should die pretty fast.
glyph of corruption is a good choice for prime, you could also add unstable afflction (it's nice for leveling), and haunt glyph is also needed while raiding, might be good while in dungeons but doubt it's a game braker while leveling. For major those are more utilities glyphs. Shadow bolt is nice, since it's your filler and you use if when nightfalll procs (+ glyph). Might want to take glyph of soul link to reduce dmg taken if you are multi pulling.
at the current state you can level a lock effectively almost anyway you want.
If your level 72, and mobs dont die from haunt + shadow bolt, im pretty sure your doing something wrong
that being said, on elite mobs, just make sure you have haunt + dots up and fill with shadow bolt, then you should be alright
Glyph of Corruption and Glyph of Lash of Pain are great glyphs for levelling (assuming succy is stil superior at that level)
Please correct me if im wrong, been a while since i was level 72 and a lot might have changed
dot (Unstable affliction > corruption > CoA in terms of damage. CoA is probably not necessary till level 80) up several targets (3-4) at a time and drain life as a filler, haunt on CD for the heal and improved damage. Dont use shadowbolt as a filler while leveling. Drain life is equal in damage but has a higher burst and you heal yourself; only use shadowbolts with instant procs. Especially when you reach level 80, you'll have so much mastery on all the quest gear, that drain life will be your better choice in any case.
The only three usefull prime glyphs for leveling are haunt, corruption and unstable affliction since you're using your voidwalker. Major glyphs: soul swap for sure and then you can decide between shadowbolt(mana saver)/lifetap(time saver) and soullink/shadowflame/healthstone for survivability (I'd take soul swap, soul link and shadowflame).