I'll let him down gently shall I. You will find that best answer you will get is by trial and error because no one hear is going to give you a full run down on there gold making/selling simply because you are the compitition and the less competition there is the better for them so yeah try difrent things most will fail but you live and you learn. I had to!
/truth
but in addition, everyone isnt on the same realm. what sells on your realm usually isnt the same as what sells on mine. you might already have teams of skinners on your realm sinking the market. you might be on a small realm where one dick has 11 alts with level 3 garrisons pumping out cheap epics every day. its more of a fluid movement in and out of markets that will net you that extra 15% a day profit.
know your competitor's markets. this is a monumental task on my current realm but on my home realm, i knew people, their alts and what markets they liked to play. i could whisper player X and see when they planned to reset glyph prices and work together. whisper player Y to contract a set price for meat that you collect while skinning.
learn TradeSkillMaster. its the closest to legit botting you can get while still inside the tos. however, stay cool about it because it still falls under exploiting the economy if people get pissy. and they will when you post 500 glyphs with one flick of the scroll wheel.
and the most important tip of all--STOP SPENDING GOLD ON USELESS SHIT AND STOP GIVING SHIT AWAY
example: your bro whispers you 'hey you got any raw talbuk meat?' yeah, of course you got raw talbuk meat, but its selling for 250g per on the ah. sell it on the ah, fuck your bro. he is your bro, not your firstborn son. let him farm his own meat.
guild knows youre a botter, 'hey bud, can you farm me some skins?' 'FOR FREE?'
if your goal is to be a bro, by all means, be a bro. but bros don't get rich. you see Donald Trump in his jet with bros and hos? no. You see jackass musicians on their jets with bros and hos? all the time, till they are broke as shit living in the street, in front of a bros house.