Realm First 90
-Empty Inventory except for necessities (Flasks, Food, Pots, Reagents, etc)
-Less Down Time
-Maximize time earning Experience
-Argent Pony Bridle for bank trips, mailbox, etc.
-Engineers can use portable mailboxes to mail items off and Jeeves for repairs
-Turn autoloot on for less time spent clicking etc. Or use AoE Loot or the Loot-a-rang.
Mists of Pandaria Gold Theorycrafting
-Selling leveling kits for all professions to new characters made after the Expansion drops
-A few weeks prior to MoP start listing Food, Flasks, Pots, and their mats. List everything that can potentially help someone to level faster in game. People will be racing for level 90.
-Fishing right after the Expansion. People will need food for buffs etc. for raiding, dungeons, buffs, etc. Miners, Herbalists, and Skinners will all be out competting while you have all the fishing pools to yourself!
-Do some research on things people will be rushing to get in the early days of release (pets, craftable gear, new toys/mounts, etc.) and start stocking the auction house with the materials used to craft these items or just listing the items themselves.