Yay! This morning I finally maxed out leatherworking, woot! I already updated my Leatherworking guide with some general information about getting to 375, but now that I've done it I will definitely add some additional tips.
The first thing I discovered is that Riding Crops are actually a decent way to go. True, it requires 5 primals (one of each) but many of the other high-end recipes require 6-8 primals anyway. So by comparison it's actually a decent deal if you have an enchanter to feed you the other mats (which I do). I found that farming 1 primal air and 1 primal fire was less painful than farming 6-8 of them to make something else. Plus you get more variety in your farming since you can switch locations for each type of primal needed. So I made a handful of riding crops until the recipe turned green at 370. It helps if you have an alchie buddy to do the transmute for you, but if not just sell the primals and buy the might with the proceeds. You actually come out ahead that way in terms of cash value if you have the patience to wait on the sales.
The other recipes that I used heavily were the Heavy Clefthoof items. These will take you all the way to 375 between the three of them and they only require Honored with Cenarion Expedition to purchase. Anyone can easily achieve Honored status just by completing all the various quests in Zangarmarsh and Blade's Edge.
I know that the Heavy Clefthoof mats look daunting, I had the same thought when I first saw the 30-40 clefthoof leathers they required. As you may know, these have a 10-15% drop rate now that they've removed the clefthoof mobs from Blade's Edge. However, the alternative is the Felstalker gear, which requires 6-8 primal airs to make. I don't know about you, but farming that much air is enough to make me light-headed! But the main reason I would go with the Heavy Clefthoof items is that aside from the boots, I was actually able to recoup a lot of my sweat equity from them on the auction.
On my server the thick clefthoof leather goes for around 3g each. If I buy 34 of those, I'm sitting right at 100g invested, not counting the other mats needed (roughly another 40g). I was able to sell the pants for about 100g, so for the most part I got a reasonable return on my investment. I would absolutely be losing money if I bought all the materials, but I tried to farm half and buy half. This way I would still be making a small profit when the item sold, without driving myself insane with farming. My suggestion would be this: once you sell your first piece, use the money to buy half the clefthoof leather for the next item and farm the rest of it. This will give you a happy medium between farming too much or blowing all your gold, you should come out even or maybe up a bit in terms of cash.
Now if you wanted to go with the Felstalker gear, you'd probably lose most of your money. I've seen the bracers going for as little as 35g on the AH, which barely covers even one primal air! I don't know about you, but if I'm going to farm primal air I sure don't want to just give it away to some stranger for a song. I'd be surprised if you could get even half your money back on one of these. The only reason I would make them is if you want the gear for your hunter, or you have people feeding you the mats. I actually did make a couple of pieces to save for Korlyn when she reaches level 70. Don't worry, she'll pay me back by being a great farming resource =)
Also, you may notice that some of these recipes I've mentioned are yellow to you. I had some trepidation about this too, but I got really good points from the Riding Crop, which was yellow from 360-370. I still got a point for every one I made until it went green. I also had very good luck with the Clefthoof pants and vest, so don't be afraid. Ironically, the only time I did not get a point was at 374 on the Clefthoof vest. I was pretty annoyed by that too, lol. But in general the yellow recipes worked well for skilling up.
And now I'm the proud owner of three epic Windhawk recipes! Here I thought my days of farming leather and primals were over, but that was just the warm-up it would seem...