While this has been posted MANY times before, I will share my own personal method of using this exploit because I find it easier.
1: Have your pet out.
2: Have Aspect of the Hawk active(ASPECT1) (any aspect will work)
3: Click off ASPECT1
4: Click Camo immediately.
5: Click ASPECT2
All you will see is that your aspects have swapped from ASPECT1 to ASPECT2 as it would normally work. However, if you click the now "inactive" ASPECT1 you will now have BOTH active.
To repeat for ASPECT2,3,4,5 all you need to do is dismiss your pet then resummon it. This resets the mechanic allowing you to now...
1: Deactivate ASPECT1
2:Camo
3:Activate ASPECT3
4:Reactivate ASPECT1
*VOILA
This method requires no auto-running and much less timing which can be a pain with varying latencies. I am able to get Hawk, Fox, and Wild up at the beginning of all my instances before the first pull and I can instantly get Hawk and Fox working as soon as I respawn in a battleground.
Just so you know, if you active Cheetah and Pack together, one will overwrite the other and you'll see the 2nd tooltip read "0% increase"