This is where alts come into play. You can have only 1 mastery on account, witch means you can get alchemy over 60 (not that alchemy at higher level is any good), but everything else is going to be bellow 60 (2 more crafting/gathering), or 40, (those three already higher, plus 3 more crafting gathering). Everything else can get to L20.
So create alt for each of things you like to do, for example:
Main - alchemy
Alt 1 - mining
Alt 2 - herbalism
Alt 3 - woodcutting
Alt 4 - tailor
Alt 5 - cooking
Everything will be nice and dandy for a while, but then, as your level rises, you will require for example to gather higher level mats, so your alts needs to be leveled and equipped to survive while gathering. This will take lots of time.
Another thing that I suggest - use pet to produce mats. On main you can rise all 3 pet crafting, as that one is going to be all the time on. There is no reason not to have it producing mats while you quest/do your things...
Each gathering alt should have pet producing that mats as well, this will help you getting required mats more quickly and in good quantities to level crafts later. (requirements are high)
Only problem with this is that pet has limited gathering capabilities, and this is not fixed yet in the game. (up to level 61 only atm)
Another thing I wish I started earlier is planting. Planting is easy, you can plant up to 5 pots bellow L20 and up to 10 pots rest of leveling. Leveling is pretty easy, so daily if using latest seeds you will level couple of levels even if in higher level (for example I have it at level higher then 50, and still gathered 2-3 levels last night). This can be easily done on more then one toon, and best pot to use is Zeus in my opinion. (13 dias in CS - 65 dias to get you started). I recommend using pixi water/soil.
Positive side: it does count in 1-3-6 rule, so you can be master in something, and master in planting, gives processed items. It is fairly cheap, except starting cost of pots. For 130 dias you can get 10 pots, but then it costs around 10K (at low level less then that) per run to gather couple of stacks of mats.
Negative side: takes space in house, so if you have furniture, you have to expand your house, but not very costly anymore, and with Dias NPC, you can get enough dias to get pots/expend house on alts as well. Another negative side is that you might get mats that are over-processed. For example, my friend has a cook who needs high level herbs that are bundled, but planting gives him saps. Add to that annoying mage asking for food.... you get picture...
Good luck with crafting. It is fun, too bad it does not pay much...