I do a bit of everything despite the fact that I don't sell gold. I'm a hoarder when it comes to the shiny!
I have a couple hours free in the mornings after my kid goes to school so I generally run GarrisonBoss during this time to get all my Missions, Ore, Herbs, GRs, and profession cool downs done. Then depending on current prices on the AH I'll throw up some bags, dusts, and profession mats. I never flood the market or undercut the hell out of other sellers in hopes of staying off the radar. Most days I post less than twenty things and sell between 90-100% of it. I have three max level engineers so every 10 to 15 days one of them has enough cool down mats for me to put a Sky Golem on the AH for 8-10K and it usually gone in under an hour. Additionally, I generally gather enough sky shards farming Pandaland every couple days to sell an Alani kill in the trade channel for 8-12K so someone can get the Reins of the Thundering Ruby Cloud Serpent mount.
After that I get HBRelog going and put my farmers to work world farming cloth, furs, skins, greens, blues, and vendor trash. I switch them around so they are in different areas through out the day (Draenor, Pandaland, and Cataclysm zones). Panadaria, in my opinion, is a gold mine for farming right now at least on my server. All the zones are dead and I've got half a dozen profiles that bring in 1K or better GPH just from vendoring trash, greens, and greens and blue I tailor from the cloth drops (Potion of Luck is the bomb). I usually run the farmers in three hour blocks and stagger them through out the day. Each farmer runs for 9-12 hours a day.
If I have a toon that needs gearing I'll run them with DB or BGbuddy for a few hours in the evening when the ques are fastest to get them some better gear, but I don't go crazy trying to gear them up if it's not on my main account.
At the end of the night I run GarrisonBoss again for all the same tasks as the morning run. After that I set up two Druid Farmers to run a couple hours in stealth gathering ore and herbs, and another to fish so I can keep my toons loaded with things to trade in at the Garrisons for GRs or professsion mats. Garrisons make you easy gold when you run high level missions with Scavengers and Treasure Hunters.
I'd say my break down of gold making is 50% world farming, 40%AH, and 10% from Garrison Missions.
Things that sell great for me on the AH:
Bags:
Royal Satchels - get a tailor toon exalted with August Celestials and run a farming profile in Pandaria to get the mats needed to make them and with Song of Harmony you can kill it at the AH by pricing them 25% lower than Hexweave Bags.
Embersilk Bags - Tol Barad is a ghost town and there are tons of humanoids that drop the cloth and greens needed for dust to make these. Get a good profile there and use Potion of Treasure Finding and you'll make more bags than you can sell. PS - Don't flood the market. Try listing 2-5 early in the morning and avoid selling them on the weekends when the market is flooded
Profession Mats:
Embersilk Cloth - Hit or miss with this one. If the market is flooded with cloth make bags. If it's also flooded with bags make greens and DE and sell the dust.
Frostweave Cloth - Highest selling cloth on my server, but your server might be different. Even my best Frostweave Farming profile doesn't farm these as fast as I would like, but there's a demand on my server and Icecrown is dead most of the time so why not farm it right?
Herbs and Ores - I have better luck selling these in stacks of 50 and 100 than I do selling them in stacks of 200 for some reason. Must be a psychological things with the buyers. Again, don't flood the market.
Fish, Cooked food, and Pots on Tuesday and Sunday nights - Raid stuff......gotta have it
Other stuff:
Desirable Greens, Blues, and Purple drops
Giant Dinosaur Bone - in stacks of 500 or 999
Meat from WoD beasts