So, being a recently dinged 90 hunter I have found many issues with the hunter class that make the play style slightly tougher than it has to be.
Now these macros are most likely known by highly skilled hunters but if one of these helps you out, I just hope you're not horde.

The first macro is simple and just helps within arena or even battlegrounds when faced in a 2v1 situation

Macro 1;

#showtooltip
/stopcasting
/stopcasting
/targetmouseover
/cast Counter Shot
/targetlasttarget

The above macro requires two sets of Counter Shot spells bound to your bar, as one will be your single target in one versus one situations, whereas this one allows you to stop casting such as 'Cobra Shot' and instantly switch to the opposing target in a two versus one that may be casting a heal or a chaos bolt. This will ensure you stop attacking the target and instantly fire a shot at the caster, if necessary change the /targetmouseover to /target focus if you rather focus one enemy in a two versus one than hover your mouse.

Macro 2;

#showtooltip
/stopcasting
/stopcasting
/(Spell Name)

Macro 2 is mainly required for all spells a hunter uses, as it is important that your spells are timed perfectly, hunters that use cobra shot or steady shot will understand that when moving you can become annoyed at the one second left casting your shot until you can place a trap or binding shot etc... therefore making this macro to all of your spells will ensure you stop casting you cobra shot / steady shot to fire your others instantly.

Macro 3; (Two part macro)

#showtooltip
/cast Arcane Shot
/petassist
/cast Furious Howl

#showtooltip
/cast Freezing Trap
/petpassive

These two macros work in conjuction with each other as when entering combat a hunter most likely opens with arcane shot, this means your pet will begin assisting you and will attack the target you're hitting, afterwards if your pet is a wolf it will cast the Furious Howl buff which does not usually apply when set to auto on your pets hotbar, therefore with the buff lasting 59 seconds and the cooldown being 45 seconds, you will have a permanent 5% critical strike buff when fighting.

As your pet is set to assist, when casting freezing trap you do not want your pet to still be attacking so the /petpassive stops your pet from attacking the enemy and breaking the freeze trap.

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These are the macro's that I know, feel free to past any others that you feel may be beneficial to other hunters below, hopefully these helped you guys out.