I'm low on gold and don't want to buy gold. I heard that farming dungeons was a good way to make gold. but i don't know which ones.
Or do you guys have better ways of making gold.

Go Instance and get items, sell them in AH. You can also buy lower items in AH and sell it in a higher price. Yes, professions is a another way. Like mining and blacksmithing, sell Ore and items you make in AH in a reasonable price. Players will certainly buy them.

If you need gold in no time, ordering online is the only way. You can try this site. www.fzf.com My friends and I sometimes use it since they always offer the best service, fast delivery and safe. Btw, here is their coupon code "wow" for 5% more. You can have a try!

I have a better way of making gold, get a life.

Invest into a Profession. Trust me it doesn't sound pleasant but it defiantly is an excellent way to farm gold. My first 3 years of playing WoW I never had a profession. Finally I decided to get Mining and I love it. I make approx. 500g an hour of farming. You also come up on some nice gems and other minerals that stack up and sell for more the more you gather.

daily quest,

auction manipulation

farming

proffesions

those are pretty much the ways you can make gold...