Hearthpwn

A midrange shaman list with elemental synergy. Start the game with cheap minions, tokens and totems, buff them with Earthen Might, Flametongue Totem, Dark Iron Dwarf or Fungalmancer for good trades, clear the board withFire Plume Phoenix or Fire Elemental while building up your own board and finish with sturdy minions or Bloodlust. A decent deck if you want to play something different but if you want to get high up on the ladder then you might want to look for another deck.

Mulligans:

Aggro: Against faster decks you want Argent Squire,  Fire Fly (+ Earthen Might), Primalfin Totem, Tar Creeper and Lightning Storm. You can keep Flametongue Totem if you have a 1-drop or Primalfin Totem. You want to build up your own board while keeping their board clear with good trades and a Lightning Storm if they overextend.

Control: Against slower decks Argent Squire,  Fire Fly (+ Earthen Might), Primalfin Totem and Vicious Fledgling. You can keep Flametongue Totem if you have a 1-drop or Primalfin Totem. You want to put as much pressure as possible but beware of board clears, you dont want to loose too much at once since you lack card draw. At the later stages of the game you are better off with 2-3 sturdy minions instead of a full board with low health so use buffs to trade in your weaker or damaged minions instead of your big, healthy ones.

Replacements:

-Dark Iron Dwarf, -Tol'vir Stoneshaper, + 2xBlazecaller. Blazecaller is probably the best elemental in the game and can either clear midgame minions or take the last bit of health of your opponent.

-Fungalmancer, +The Lich King or Kalimos, Primal Lord or Al'Akir the Windlord. Each one of those cards has its advantages but I would rate them 1. Lichking, 2. Kalimos and 3. Al'Akir. The Lich King has the best body and offers great cards,  Kalimos, Primal Lord is very flexible and he supports the elemental synergy but requires it aswell and Al'Akir the Windlord supports the elemental synergy aswell without any requirements and he can be an unexpected burst (especially with Flametongue Totem or Earthen Might) but otherwise he has the weakest body. Al'Akir also has the benefit that he is usually not played and you could change that, even if he is a bit weaker than the other 2.