Herb/Alch is always good, as it has the bonus of having the most sellable products of any crafting skill. Also the transmutes are great. I have this on my rogue and its very useful. I don't know how the up-coming changes will effect it though, as you will soon only be able to have 2 elixirs active at any one time. One from the new Guardian school and one from the Battle school...
As a LW/Skinner on my druid, I can honestly say, if you want to be making your own armour regularly as you level you will need to either buy a lot of extra leather/mats from the AH or skin you heart out. I found that during leveling the armour was never suitable for my current level and didn't really catch up until the late 40's. Drops were always better. Now at 70 though about 40% of my items are crafted so its turned out to be worth it, although very expensive to get the last 10 points from 265 - 375 :S shudder...
Oh and to answer your last comment, out of the 2 options I'd say Herb/Alch is the more profitable.
Edited, May 3rd 2007 5:19am by kadanis