TailoringFollow

As Tailoring doesn't need it's own support profession any gathering one can put cash in hand. At lower levels of skill I have found mining to be profitable, with a stack of copper or tin going for 80s-1g on my server.
At higher levels of skill herbalism really shines as people want high level herbs for their alchemy. Even at lower levels swiftthistle (found with Briarthorn and Mage royal) and Wildvine (found with Purple Lotus) sell well, Swiftthistle for upto 8G a stack, Wildvine upto 15g. Of course these are harder to find than copper ore.
Another possibility would be skinning, many things you kill will be skinnable, beasts and Yetis, so require no looking for. On my server leather does not sell to well.
Finally, do not forget fishing. While low level fish, except for Deviate fish from the Barrens, do not sell well, mid-to high level fish, Oily Blackmouth, Firefin Snappers, Nightfins and Stonescale eels are very profitable.

In summary, mining/herbalism+fishing brings in the cash.

HTH