I have 3 now, Argi (Bad choice I know, but it's a spacegoat), Anubisath Idol, and Fossilized Hatchling. Should be getting another level 25 boost here today, so I'm contemplating what to use it on. I did catch an Unborn Val'kyr last night after 10-15 minutes searching, so potentially boost that? But ...

As a new player (skipped MoP) What would you recommend as a leveling method now that Garrison leveling is no longer a thing?

Still not sure, so just going around doing the various quests/achievements