First off all, walk in to a merchant shop (I recommend a fighting chance).
Second take a bow aim at the merchant's head and pick em off.
If they don't die pull out your blade and kill them.
Make sure there's only 1 person in the shop.
When they die take as much stuff as you can.
Once you walk out be cautious. Drop all the items you stole (the items with a red hand by it).
Go to jail or pay gold.
Then go back to the store and take the items.
This cheat is good for fencing gold for the Thieves Guild.