One of the oldest enchanting recipes, fiery weapon, is still one of the best moneymakers in the game! It it used by leveling toons because it is a great stat modifier for dps and it works on BoA gear for alts. The recipe requires 4 small radiant shards and 1 Essence of Fire. These mats are cheap, unless I am the one selling them! Try to keep the market clear of these mats at cheap prices while you work the enchant market. I can usually find these items for 2-3 gold each or even lower. Sell the enchant for 150 gold or better if you can. On my server we seem to sell about 30 of these per week right now.
you will see people post these for much less, so you have 2 choices; buy them out or let them sell them cheaper. you may have a 3rd choice which is to undercut them but I hate undercutting if it means low profit margins. my strategy is simple, buy out the mats in the AH and buy out the cheap enchants, relist 4-5 at a time for 150-100 gold each and watch my profits soar!
Don't forget about those mats either, I usually relist the Small Radiant Shards for 15g each and the Essence of Fire for about 20g each.