Currently I'm seeing JC'ing being most profitable by making the Rare Rings.
The shuffle doesn't seem as effective as it once was. I'm finding that Uncommon Gems are currently selling for squat and are better off being being made into rings/necklaces and selling the Rares and just disenchanting the Uncommon ones.
Because I haven't levelled my Enchanter past the Wrath stage I can disenchant the rings/necklaces however I'm still finding it mostly profitable without that.
Band Of Blood seems to be a big winner on my server, the mats cost about 450g while the Ring itself is selling for 950-1000g