Question: skyrim how to become a master thief?
Answer: Note: Spoilers.
Choose a sneaky character. At the start of the game pick a race that lends itself well to stealing and being light on your feet. ... 
Get a skill boost. ... 
Learn to Sneak. ... 
Join the Thieves Guild. ... 
Make invisibility potions. ... 
Get married. ... 
Get the right garb.