Below you will find how I make a least 2k gold a week by doing almost nothing. The profit could be expanded if I wasn't so lazy and actually farmed the mats instead of buying uncut gems off the AH.
Here is a list of the cuts that will make you the most money(on my server at least, I would think that these kind of cuts and prices wouldn't fluctuate to non-profit levels on any server):
JC TOKEN GAINED CUTS
Enduring Forest Emerald (Grn)
Solid Sky Sapphire (Blu)
Chaotic Skyflare Diamond (Meta)
REP FACTION CUTS
Runed Scarlet Ruby (Red) Kirin Tor - Exalted
Smooth Autumn's Glow (Ylw) Sons of Hodir - Exalted
WORLD/BOSS DROP
Inscribed Monarch Topaz (Org) World Drop
Sovereign Twilight Opal (Prp) World Drop
Austere Earthsiege Diamond (Meta) King Ymiron - UP
Buy / Prospect / Farm the mats to have at least 2 of each of these gems up at all times. Place the auction on a 12 hour duration, reason being the prices fluctuate so much that if your gems don't sell within the first 3 hours, you've bound to be undercut.
Set an initial cutoff price for re-cutting and listing. For me, I buy 800g worth of mats, and once I make that 800g back I buy more mats. Right off the bat it will seem that you are spreading yourself out too thin, until you see that you have 1k in your mailbox with 15 auctions still up. I was trying to find an alternate way to make money without D/E'ing, and this is the best I have come by. Hope it helps!