For my first 5 box team I just went with:

main - skinning/mining

alt1 - tailoing

alt2- enchanting

alt3- jewelcrafting

alt4 - leatherworking

so far it is working on nicely. My enchanting and gathering are always kept at the max since I level mostly with instances. The things I make with jewelcrafting are DEable so that makes enchanting that much easier and also helps suplement the cost (JC is a pain to level). Like majestic said, tailoring is always a good choice. I'm going to take his advice and put tailoring on all my alts because 1)the are all cloth casters and 2)cooldowns are a great source of income.