Well this is something i have been doing for a long time, and have seen a few people been doing, but rarely.
Requirments:
-A decent amount of gold to start with (gotta spend some to make some) (atleast 8k)
-A personal guild with ATLEAST 2 free bank tabs you can use
-Smarts
The Guide:
1. Before doing ANYTHING, you need a buyer, so go to Dalaran and say this in trade "/2 WTS Profession Kits! Will get you from 1-450! Enchanting-xKG, BS-xKG, Leatherworking-xKG, Engineering-xKG, Alchemy-xKG. PST for more details."
*Fill in xKG with how ever much you spend on the mats + a good tip for yourself.
2. You probably will get a few whispers, have them tell you what package they want, so say it was blacksmithing, go and buy all the materials here: WoW Blacksmithing Guide 1-450 | Blacksmithing Leveling Guide. This website has all of the profession guides. MAKE SURE YOU READ THE GUIDE, SOME OF THEM REQUIRE RECIPES TO BE PURCHASED FROM A VENDOR, IF YOU WANT TO BE A GOOD SELLER, BUY IT FOR THEM!
3. Put all the items in your guild bank and tell them that your ready for them.
4. Invite them to your guild and tell them to deposite the decided on amount of gold. Once it's in and you have withdrawn it, rank them to a rank that can withdraw unlimited from the tab you used.
5. Send them the link to the guide you got the mats for (WoW Blacksmithing Guide 1-450 | Blacksmithing Leveling Guide) and tell them to just follow that, and tell them any exceptions that you have made.
What i suggest is to purchase a little bit more than it says to on the guide, then charge them like 1-2k extra so they dont run out of something. TELL THEM THAT IF THEY RUN SHORT OF SOMETHING YOU WILL COVER IT FREE OF CHARGE! It always makes them feel better.
I have been doing this for months and sell about 5 kits a week (rarely selling them) and make a 2k-5k profit on eachone, depending on the current server prices.
I searched and didn't see anything, so if this is a repost go ahead and delete.
Post your success stories, i want to hear!
EDIT: The prices i use are Enchanting-6.5KG, BS-8.5KG, Leatherworking-5.5KG, Engineering-5.5KG, Alchemy-4.25KG. BUT IT ALL DEPENDS ON YOUR SERVER PRICES!