ALSO, if you're a hunter Art, put your pet on "passive" when in dungeons. Otherwise, pets will run in and steal aggro from the tank or go crazy and draw in other monsters. Keep him on passive next to you and if someone else starts getting attacked other than the tank (like the healer), send in your pet to draw it away. Also, make sure your pets "growl" or other threat generating abilities are off when in a dungeon. When you're solo, your pet is supposed to be your tank, so then you'd have it go in and hold the monsters for you, etc.

Alternatively, if you have a good tank, just send in your pet on the main monster a few seconds after the tank has aggro, but always keep "growl" or whatever that particular pet has for its taunt turned off in a dungeon.

Hunters have "feint death" eventually which is for when you accidentally steal aggro (or are getting ur butt kicked) - pop that and then monster will go back to whoever's the biggest threat (either the tank or your pet when soloing.)

As far as aimed shot, I'd save that till monster is almost dead or at least firmly in control of whoever is tanking.