So lately I've been looking into the jewelcrafting profession, and I've gotten some pretty good results with minimal effort.
Basicly, it's the normal plot of just buying
[Adamantite Ore], prospect it and cut the blue gems. But before you do that, calculate the price you're gonna pay for the ores.
On my server specifically, I've got these prices:
Total average income on blue prospect: 38g
Now, you've got 18 % average on proccing a blue gem based on wowhead data (3% chance on each * 6).
Additionally, you get atleast 1x green gem and 1x
[Adamantite Powder] worth approx ~ 1g.
Okay so lets calculate the maximum price I've set for Adamantite Ore: (4*0.18*38 +1)*0.95 =~ 27g
That's the maximum amount based on NO CUTS. But to really make a profit you need to buy cuts that generate revenue. It would be wise to have cuts for all the blues so you can use every single gem you prospect. Generally a cut would add 20% additional revenue based on which designs you use, so make sure you have a alot of cut designs to choose from so you can use the ones that are the most profitable on AH at the given time.
Also, I often see cheap uncut gems that I just cut and make a quick 5-10g profit. Pocketchange maybe, but still ...
EDIT: Instead of buying the green lowlevel gems directly, it might be wiser to prospect on tin ore and mithril ore to generate the gems. Was alot cheaper for me on my server