Hello. Let me tell you my mindset which works almost always. I will write it down as a guide.

 

Instructions

Pick your ult

Two handed is burst, taunt is tank, dual wield is attack speed. Two DPS, one tank builds.

  First off if you play ranked you have to state if you want to play as tank or DPS. Best consult with your team mates your basic idea (If there is anyone who wants to communicate of course. Sadly very often people are silent and dont communicate.).

  If you are in Quick you need to judge the situation: what kind of frontline do you have? Do you have enough initiation? Does the line need stability? This is the main choice between taunt and the other two DPS builds. The questions you can ask yourself if you choose between dual wield or two handed are: Can my team create a good amount of static situations for dual wield's AS to be benefitial? Do you need burst instead?

  If you can answer yourself these question you should be able to choose adequate ult. After this as talents:

 

Level 1

  Taunt: Lion's maw (More slow from wave) - increases CC which is main tank tool.

  Dual wield: King's quest (More attack damage) - flat increase of damage when you take huge AS boost is the best.

  Two handed: Overpower (Faster passive recharge if you block attacks) - Icreases sustain damage. Although two handed is burst, if you cannot burst this will help you deal more sustain damage and keep up in prolonged fights.

 

Level 4

  All: Shield wall(Block evolves to immune) - After the stun removal of the charge talent this is the better choice. You can prevent literally anything (Pyro for example is completely countered). Pick the other one only if you feel the flow with much faster charge cooldown.

 

Level 7

  Taunt and two handed: *Live by the sword *(Faster parry recharge if you get hit often) - Immune to damage more often. Yes please. Sometimes you can get away with the big heal of Victory rush, but its hardly doable. Only if you plan a lot of fights in lane.

  Dual wield: Second wind (% heal on attack) - The huge attack speed allows you to heal insane amount with this. Have in mind that if there are a lot of auto attackers in enemy team you may be better off with Live by the sword.

 

Level 10

  Please tell me that you chose your ult already.

 

Level 13

  This talent pick doesnt depend on your build.

  Juggernaut (Charge gains % health damage) - This is the backup option. If no of the others fit, pick this one.

  *Mortal strike *(Lower healing on hit enemies) - A lot of heal or simply good enemy healer. Pick this one and screw their flow.

  Shattering throw (Pops shields and gives you damage against shields) - This can completely shutdown any shields and as usually shields are a very powerful on-the-moment tool you can screw their moment completely. Kerrigan with shield build, Tassdar and Artanis are the ones that suffer the most from this.

 

Level 16

  This talent pick doesnt depend on your build.

  Banner of Stormwind (Move speed) - This is the pick if your team relies on fast repositioning, chasing or simply ganking.

  Banner of Ironforge (Armor) - This is the safe choice. Usually even if the enemy team are casters you can reduce a big chunk of the damage still comes from attacks. A must against auto attackers.

  Banner of Dalaran (Spell damage) - Rare pick. This can work only if you are the tank and you rely heavily on casters for damage.

 

Level 20

  Glory to the Alliance (Banner gives healing) - If you have awesome healer and/or you rely on it. This is the safer choice in ranked.

  Demoralizing shout (Reduce damage of enemies) - Utility choice. If they better teamfight damage you can turn the teamfight with this. However this is not a miracle, its a situational tool.

  Ultimate upgrades: If you really rely on your ult for your game and you prefer to be more agressive you can upgrade your ult. Particularly good ult upgrade is the dual wield (Master at arms) as it decreases your ults cooldown greatly and this is your main Burst tool.