The fifth way is always to set auctions for 48 hours and put a buyout price about 4-6x the value to an NPC vendor. Once again, you must check the Auction House current prices so you don't over or under value your item. The buyout price allows impatient bidders a way of getting their items quickly and your faster.
The sixth way is to mail your major items to your mule for Auction House Placement, dump the rest of the garbage onto the NPC vendor.
Each stack will sell at Auction House for 5-10s per stack easily and up to 20s per stack if the demand is right, low level green items 5-10s each.
The seventh way is not to choose your crafting profession too early. You're able to drop one of your gathering professions for a crafting profession once your flow is good. There're some useful ways for your reference. Let's get started.
The first way is to collect six slot bags as quickly as possible. Some will drop as loot and some can be bought from tailors, you can do a /who and /tell and offer to buy COD via the mail system so you don't have to buy from an NPC vendor or go to an Auction House before you are ready.
The second way is to keep notes of how much a stack of resources (light leather from skinning, copper ore from mining, silverleaf and peaceblossom from herbalism) sell to an NPC vendor but don't sell to the vendor.
The third way is to check the Auction House prices using the search facility and take note of the starting and buyout prices for the stacks of resources you are selling. Many items have a buy-out price up to 10-20 times the price an NPC vendor will buy from you.
A couple of hours work at toon level 6-8 will give you 3-4 stacks of light leather, 2-3 stacks of herbs, 1-2 stacks or metals bars and if you are working in an area of humanoids 1-2 stacks of linen cloth. You don't waste your linen on bandages, at least not yet.
The fourth way is not to waste bag store space on grey usable items, ruined pelts and broken teeth and so on, unless you are filling up an inventory for the run home. What you do is to keep green items for Auction House sale if your toon (or an alt) doesn't need them.

Buying unneeded items early eats money.
Buying unneeded skills early eats money.
Enchanting eats money.
Engineering eats money.