For profession 1 you want gathering income that you can track. Such as either herbalism or mining.
 
	For profession 2 you want something that makes money, but is not tracked because you cannot track two things at once. So either Enchanting or Skinning.
 
	I normally do Enchanting and mining, then drop mining for Tailoring at 60. I find waiting/finding enchanters to be annoying so I like to do them myself. Tailoring is almost mandatory for raiding for the bloodvine set.