Diablo 3 has a lot of cool features, the trouble is that it likes to hide most of them from you by default. Elective Mode is a complete game-changer that you have to hear about from a friend to know to unlock.
A friend told me about another hidden tool last night: the Move key. It saved the life of my permadeath Monk last night, so I'm passing along the tip to you.
The Move key is an unbound entry in your keybindings menu. Once it's bound to a key (I use W for quick access) it can be used to move just like a click/hold of your left mouse button. Tapping the key orders a one-time move command and holding the key causes your character to follow your mouse until you release--just like the mouse button. But unlike your mouse button, the Move key completely ignores enemy hit boxes, allowing you to force your character to move to a location instead of attacking the enemy standing there.
This is incredibly useful, especially in boss fights, where large hit boxes can often overshadow health globes sitting on the ground--making it practically impossible for you to move your character to them and receive their lovely life-giving powers with the mouse controls. It's not just health globes though--having a designated move key that can't be overriden by attack commands makes it significantly easier to fine-tune your positioning no matter what you're up to. This is especially important when you're kiting packs with your Demon Hunter: on Inferno, all it takes is one stutter step for the minions of Hell to catch up and tear you apart.
Last night, my hardcore Monk got trapped by some summoner and waller elites. My health was getting low and there were 3 health globes half a screen away. The trouble was that there were about 8 NPCs standing on and all around those health globes. My left-clicks were forcing my Monk to attack the scaly demons when all I really wanted was for her to run like hell straight for those permadeath-defusing red floaty balls. After furious mouse-clicking, I remembered the Move key, and with one tap on the keyboard got my Monk to do exactly what I wanted.
The Move key saved me from tearing my clothes, covering myself with ash, and mourning the permanent death of my level 24 monk that I've invested over 16 hours into so far. I hope it'll help you too.