Funny you should mention this scenario, as my brother is an enhancement shaman and I'm a Marksman hunter. We duel for fun, and for the most part I fool around, I'll go into melee and just Wing Clip him over and over again until he kills me. I'm not much for dueling, but when I actually try I almost always beat him.
VS Enhancement Shaman:
First the range is very important. Anything you can use to slow the shaman down is important, either by Wing Clip, Conc Shot or Frost Trap. He will be doing the same to you, trying to slow you down to get you into melee range. If he gets into melee range with that 2hander, a couple good windfury's and you're out. You always want to kite an enhancement shaman, never let them lure you into their totem traps.
Getting their mana low isn't nearly as important as always staying away from them. They'll eventually go through their mana either by trying to keep themselves alive, or constantly throwing shocks at you. Just be patient, and let them come to you. If it looks bad, try a Freezing Trap, get to range, bandage up, and start all over again.
VS Elemental Shaman:
We've all seen them, the shamans who think they're mages, and just love to spam Chain Lightning or Lightning Bolt at you to try and kill you. Make no mistake these guys can be lethal and can easily take you out with a couple of well placed Lightning Bolts. The object here again is to kite them, however most Elemental Shamans know their own range, and know how to lure you back in. Don't be fooled, always keep your distance, and if you see them casting, quickly jump out of range so they have to either run up, or hide themselves.
The key with an elemental shaman is to always stay between 36-41 yards away. Wittle them down, drain their mana, but worry more about their HP then their actual mana. Most Elemental Shamans I've fought tend to only pay attention to their nukes, and negate their healing completely.
VS Resto Shaman:
By far the worst type of shaman to fight against. Earth Shield along with their many other talents, it makes them near impossible to interrupt their spell casting by normal means. It's a mana fight here, they can constantly keep themselves healed and wittle you down before you know what happened. Again the key is distance, a Resto Shaman can easily stay in one spot and constantly heal themselves over and over again.
If they aren't attacking you, don't get close. Use Auto-Shot only and save your mana for the final battle when their mana is down to 20% or less. There's no point in wasting your mana on Arcane, Steady, Aimed Shot, etc. while their just healing themselves to full from crit heals. Keep your pet on them for extra DPS, but don't use any abilities just yet (From the BM tree). This is definately going to be a long fight, so take your time, and watch your health.
Now depending on your spec, depends on your options.
BM Spec - Obviously your pet will be your most valuable asset here. Make sure to use Intimidate at the right moment, either when he's about to heal himself, or if you just need to save your own skin. Use FD sparingly as it will make him lose your target for just a sec. Try to use your pet more to take out their totems, or if your quick enough just take them out yourself with an auto-shot assuming you have time. Use Bestial Wrath when you feel it's appropriate and you got it.
MM Spec - Again you want to stay at max range, Scatter Shot will help you with this, and keeps them stunned just long enough for you to escape. Your pet may not be as useful here, but can still help. Silence Shot is great for when you're going for the kill here. Don't be afraid to use freezing traps (just make sure no Dot's are on them), and you can pretty much just wittle him down.
Survival Spec - Wyvern Sting is just fun to use here, pisses them off and keeps a nice dot on them for when you're kiting them around. Assuming you went 0 / 21 / 40 you can also use Scatter Shot to interrupt their spells. If they get to close, Deterrence + Monkey Aspect works the best against enhancement, and you can even go toe to toe for melee purposes. I just wouldn't suggest it for to long.
Edited, May 17th 2007 2:46am by Joobishwun