Just as the title says, i'll be explaining how to make a decent profit using Blacksmithing.
The first thing that you should be doing to maximize your profit with Blacksmithing is creating Ebonsteel Belt Buckles. The mats for these are 4 Pyrium bars, 4 Elementium Bars, and 4 Volatile Earths. These belts are pretty server dependent in price, but on almost all servers you can make a great profit selling these. Every level 85 needs one of these eventually, and they often pay 250g+ per on the AH for them. On my server, Pyrite ore is about 60g/stack, Elementium ore is about 20g/stack, and Volatile Earth is like....1g each. So, adding all that up, it costs about 24g + 8g + 4g which turns out to be a really low price of 36g per belt buckle. They sell typically for 150g+ (Remember, it is server dependent).
Another way to make gold using Blacksmithing is selling the Vicious Pyrium PvP gear. New 85s (Especially alts of somebody) buy these so that there iLevel is high enough to get into heroics. The mats for these are 8-15 Elementium Bars (Depending on which one you make) and 10 Volatile Fire. Now, lets add up how much this will cost. The 30 elementium ore would cost 30g, and the Volatile Fire cost about 8g/per on my server, which adds up to a 110g cost to make one of these bad boys. If nobody else is selling these on the AH, I put them up for 1200g/per and they sell great. They usually don't go down in price to much, so you are guaranteed a decent profit no matter what. If you are having a hard time selling these just reduce the price to whatever you feel will make it sell faster. Some people also like to craft the Vicious Ornate PvP set, but I tend not to because they don't sell nearly as well as the Vicious Pyrium set.
Alright, next in this guide are the Pyrium Weapon Chains. I typically own the market on these on my server, so I can make great profit on these, it might not be the best way for you all to make gold but it's not bad. These things only take 1 pyrium bar to create, which you can get for like 5-10g depending on the server. Now, since I typically own this market I sell them for 250g+ and they do sell. Most servers however have other people selling them constantly, so you can probably sell them anywhere from 25-50g, which is still 5-10 times profit.
The final thing I will be showing you is selling the Elementium Rod. It takes 15 Elementium bars to create these, and all enchanters eventually need one. 15 Elementium bars is 30 ore, which costs about 30g (Remember, server dependent). So, I create these and typically put them on the AH for 300g+ when nobody else is selling them. Trust me, they do sell at that price. If people are posting them up however, you can still make good profit because I rarely see these things go under 75g, so even at it's lowest market value you are still making double the profit.
Extra: If you have mining as a profession I highly recommend you make Hardened Elementium bars to sell as well. These sell extremely well, and on my server they are going for about 45g/per. They take 20 Elementium ore and 4 volatile earth to make. That is 20g + 4g (Server dependent) which equals 24g to make one. You are making about double profit for each one that you sell.
PS: Check out my earlier thread if you want to figure out how to make Heavenly shards extremely cheap using Blacksmithing.
Thanks for your time in reading this guide, and I hope it helps some of you out. Happy WoWing everyone!