im a novice farmer, i farm with my warrior and my heroes, i farm realm of torment. gate of secrets, i make around 3-5 plat per run , not including golds.
i find great rares in the chests. and i farm LB points at the same time which makes farming Realm of Torment easier with increased LB titles.
also, hidden treasure running every 45 days brings me about 20k.
running is another way to make money, but personally i do not run, too many no pay scammers.
also, trading in town can take awhile if your asking for the highest prices. so lowering the cost by 20-30% helps speed the sale along.
i like to put my trade item in search, then kick on the playstation and play some god of war 2 or ff12 while i wait. helps pass the time.
i'm not a big fans of towntrades because i waste alot of playtime. but im starting to get into the routine of selling for an entire day, then playing once everything is gone.
sell of all the low cost items first, save the high cost items for the guru sell section or your own personal sell site.
another tip on selling is to check every town's search function, i find great deals in the oddest places. just sitting in 1 town spamming isnt a good idea and take alot longer than jumping around the globe. i would still be trying to sell things if i just sat in 1 town.
you could also hire someone to farm for you. request someone to farm a green you want. you buy it at half price, then sell for full price. i actually farm for people and ask for half the guru listing. so they are really happy when they get a a green for 5-10k then sell it for 20-30k. and i dont feel the loss.

hope this helps.