The new 5.2 leatherworking cooldowns from [Pattern: Magnificence of Leather] and [Pattern: Magnificence of Scales] offer an easy, profitable way to finish leveling a leatherworker, if you're not trying to hit 600 immediately. I had a level 81 alt with mid-level leatherworking I'd neglected since I already had a level 90 leatherworker, but the cooldown makes extra leatherworkers useful even at lower levels. Once you hit skill level 500 in LW, you can learn these recipes, and you can use one of them once per day (not both) to turn 20x[Exotic Leather] or 20x[Prismatic Scale]s into a [Magnificent Hide], granting one skill-up per day all the way to level 600. If you have any [Sha-Touched Leather], you might as well craft [Exotic Leather] from 500->526, before doing [Magnificent Hide] daily cooldowns.
Each time you use a daily cooldown, you also "discover" one of 82 new recipes; 74 are Crafted Dreadful pvp pieces like [Crafted Dreadful Gladiator's Chain Gauntlets], and 8 are epics that require [Haunting Spirit]s like [Spirit Keeper Helm]. These are also useful for skill-ups. Each pvp piece grants 2, 3 or 5 skill-ups per item created (head/pants/chest grant 5), and uses one or two magnificent hides. Both the cooldown recipes and the gear recipes stay orange up to 600.
The recipe discoveries all seem to have an equal probability, regardless of whether you use Exotic Leather or Prismatic Scale for the cooldown, so use whichever is cheaper. Currently on my server, exotic leather is typically 4g each, prismatic scale 9g, and magnificent hide 200g, so using 20 exotic leather at 4g each costs 80g and yields a 200g magnificent hide, for a 120g profit per day.
Grinding mobs for [Pattern: Magnificence of Leather] and [Pattern: Magnificence of Scales] only took a few minutes. I had a level 90 tank lead the way for my level 81 hunter in a cave northeast of One Keg in Kun Lai summit. On three toons with which I've done this, both recipes dropped before I reached the end of the cave, after maybe 40 or 50 mobs were looted. Normal mobs anywhere in Pandaria (including dungeons or raids) should drop them as well; I like like this cave because some of the large packs are inactive until attacked, so it's easy to keep a level 80 lowbie alive.