when i was upping my trade skills i noticed some of the items i make cost more than the reagents i bought for them.So i searched for big difference in cost to make and sell and found this Bronze Tube - Item - World of Warcraft the idea is basically getting the reagents,using Create All, and selling the created items.I know it's slow but it's steady income. Other items you could make are:
Deadly Blunderbuss - Item - World of Warcraft
Braided Copper Ring - Item - World of Warcraft
Copper Tube - Item - World of Warcraft
Of course it's best doing it with no unique items.