Most of these tips are for lower levels. Most mistakes are made at lower lvl's because you are very new to the game. Once you level a character it gives you the basic knowledge of the games mechanics and you don't keep making the same mistakes
DO NOT hack, bot, scam, exploit or ninja
as this will ruin you reputation and in some case will get your account banned. most hacks do not work and are just programs created by key loggers wanting to still your account or what ever else they can get. blizzard bans people right and left everyday for bots. so be warn they will catch you if you bot in game.
I do not support any of these in any way shape or form. there are other ways to make gold just as fast with out losing you account
if you do scam or ninja it may not run your account, but people are happy to go yelling in trade chat what you did, bring your reputation down. making harder to find and group, make friends, get in to a good guild, and hinders you gold making
no one respects a cheater.
I say just don't do it, it is not wroth your time and effort.
now on to the good stuff
Mistake 1 not looting stuff you don't need
the most common mistake made by players is only looting what they need for example a rouge not looting water because he cant use it. or a gray item that can;t be used are left on the mob
this is a huge mistake you need to loot everything that drops. this means you will need a lot of bag space this is the only thing a low lvl needs to upgrade as soon as he/she cans is bags. if you do this you are able to start getting a good amount of gold at low low lvl's
when you first get few pieces of gold it should go right into bigger bags and more of them. it will giver longer you can be out there questing and looting.
every time your bags are full EVERY TIME ( don't go dropping items to make room for others. finish the quest you are doing head back to town or mail box and empty you bags. sale everything you don't need to the vendor. every small items you pick up i don't care if it only sales for 1 copper sale it
Tip 2 Mule
A mule is a charter that stores and carry's items. its that simple..
when you first start out you will get some greens, blues, mats and other items like that, and you wont know what to do with them right off hand. some may be vendor trash, some disenchant others action house, but you wont always know right then. when your looting, vendor and using the action house all on one toon you will not be able to pick up all loot because you will not have the bag and bank spots needed
instead of always running to ah, and vendor every time you fill up. just male to your mule and worries about tossing them on ah later that day
after you are done questing and grinding for the day
every sever you play on should have a mule, this gives extra row of bags, another bank and even unlimited space in your mail box for like 25 days, so say you have a huge surplus of enchanting mats or herbs you need to lvl your poff at a later lvl you can send them to your mule and leave in the mail for the next 25 days with out worrying about it and they wont be taking up your bag space
and when you ready for them is hit the return button to send to your main that easy.
tip 3 upgrade
you relay don't need to upgrade at low lvl's ( unless your a twink) you blow thought gear so fast the quest and drops you get should keep you gear enough to keep lvling. buying up grades at low lvl is just a waste of gold and time this goes for lvls 1-35. your survivability comes from your abilities not from gear
a lot of low lvl players waste there gold on that will be upgraded in a few lvl just by a quest or a instant run don't be one of them.
tip 4 professions.
you want to pick your poff at lvl 5 that is as soon as you can. they are grate way to start making income. being a new player you want to stay away from crafting proffs because they cost a lot of gold to lvl up. you can make a lot of gold by having to gathering proffs like
skinning
mining
herbalism
when you get these proff just gather the items as you see them when you out questing don't waist time in hunting for them. every time you gather, save it and stack it up until you get a full stack full stacks sale better because no wants to buy 1 or 2 of item like ore when they need 20, 40 or more
once you get full stacks post them in ah you will a lot of gold by doing this
tip 4 go lvl
do spend all your time grinding for gold and other item,s go lvl it is easy to make gold at low lvl but faster more fun and easier at lvl 80.
so get out there have fun and lvl