To do this you need a horse and the more expensive the weapon you wield the better.

So get your most expensive weapon and wield it. Get on your horse and fast travel to either Kvatch to speak to the orc merchant, or to Silver Road in Cyrodill and speak to a merchant in green clothing.

Once you enter the barter screen, sell your equipped weapon. It will not vanish, allowing it to be sold over and over again for gold.

First you have to complete the Cure for Vampirism mission, and talk to The Count, Janus Hassidor. When you talk to him, ask him about the "Reward" conversation option, but don't leave the conversation, and keep asking him about it. Everytime you ask him about it you receive 1000 gold. Do this as many times as desired for unlimited gold.

Any time after you have finished the tutorial in the imperial sewers at the start of the game, you can kill a specific person and loot unlimited amounts of gold from them. Here's how you do it:

In the Imperial City, Talos district, find a house owned by a person named Dorian, it will be called "Dorian's House". Try to get him angry enough with you via threatening him. Once he has a low enough disposition (lower than 20) with him, he will ask you to leave. At this point kill him and go to loot his body. He should have around 40 gold and some other misc items. LOOT ALL THE ITEMS FIRST leaving the gold, DO NOT LOOT ALL. When you go to take the gold, it will glitch and keep allowing you to take the gold off him. Make sure he doesn't leave or alerts any of the guards and save before attempting this. After about an hour of hitting the same button, I had 150k gold.

First you must have completed the Thieves Guild quests without destroying the Boots of Springheel Jack. In order to do that you must simply survive a small fall near the end of the last quest with the boots unequipped.

After that go to the Shrine of Sanguine and get the quest there. Follow what the quest tells you to do and when you cast the spell, guards will try and arrest you. Get arrested. (Don't worry, all your equipment is in a chest at the Shrine of Sanguine, so you shouldn't lose anything.)

After you serve your time, you should have the Boots of Springheel Jack in your inventory. If you try to equip them, it will say "You can not equip this enchanted item at this time." But if you check your Active Effects page under Fortify Acrobatics, it should say that you still have the boost from the boots. You can also feel free to equip any other boots as well.

When picking a lock, there is a way to get it to automatically pick virtually every time, regardless of the lock's difficulty

Do the very first spring manually. Once it is in place, do the following:
As you press over on the joystick to go to the next spring, hit the "X" button a split second after you press over. The arrow should be in between the 1st and 2nd springs as you hit "X." If done correctly, and it doesn't seem to be too difficult, you will get the lock open on the very first try. It's similar to getting the speed boost at the beginning of a Mario Kart race.

Hope this works for others!