More tips:
Daily Chance!This should be a given, but make sure you have the Daily Chance active! Free items and gold! Plenty of things to sell even if you don't want them!
Posting!Posting gets you gold, your first post of the day gets you a bonus of 50 gold! So post in the forums everyday! You will notice that after a few posts, while you will still earn, it soon trickles down to nothing. That's fine because after a few hours, it's right back up to an average of 24 gold per post!
Voting!We love polls, they give up lots of free gold really easy! They do in the forums, and in the arenas. Works just like the forums, alot will tricle into a little but starts up again in a few hours.
Comments!Leaving your friends a nice comment each day gets you a nice little bonus of gold!
Puzzles!You know you love them. Sure, doing the easy or hard isn't so bad, but they only get you so much gold. Well, when you have time, try an Insane puzzle once per day. Your chance of getting items increases and your gold will significantly increase! (I average around 500-700 gold per day just on one Insane puzzle)
Shake those trees!Ah, nothing feels more like you are playing Animal Crossing than shaking the trees in towns. A great way to get about 10-50 gold really fast. And you'll also run across trash and bugs which people always want for one reason or another. Plus, if you have enough paper, you can make cat ears, they always sell for a bit of gold.
For more on what to do with all your new junk,
visit here!Vending!Not quite like having a store, vending requires a bit of an investment, time, and planning. Most people will vend with items like Sealed/Thank You letters. When the timing is right (hopefully!) they sell items for profit. This can be either very risky or turn quite a profit! Some people will even hunt through the marketplace for items that are mispriced far lower than they are worth in order to turn a profit.
T3h Vending Guild is a great place to learn more about this, and get tips and tricks.