Gamer Unit

Bethesda's role-playing epic may have been released in 2011, but many gamers, mostly on PC (they have some amazing mods) are still exploring the province of Skyrim. I have had 2 playthroughs of Skyrim, one as a mage and one as Thief.  Aspiring thieves in Skyrim should take note that a stealthy approach in the game is hazardous as our player has neither the weapon, nor the skills for becoming a thief. I always recommend using primarily one handed weapons as a melee class at the start of the game, and once you begin to get the hang of the game mechanics are a good enough level to sustain yourself against enemies like Frost Trolls and Giants. However you should take care as to not spend any skill points on the Melee class build.  This should be around level 17-20 when you can take down these creatures with ease. At this point, you should change your class to  a Thief.

The first step you should take to doing this to go back near Riverwood and visit the Guardian Stones again. Change the active stone to the Thief Stone. This will give you a headstart on your road to becoming an llusive thief as it will improve ALL your eight stealth skills up by 20%.  Now there are a a handful of options you have to increase you stealth skills. Since there are eight skills to level up, we will focus on the most crucial one for a thief and even an assassin. The "Sneak" skill can be levelled up in two ways. One will involve taking advantage of a glitch, which I do not think has been patched yet. The other is legitimate, but will require a lot of money as well as patience. 

GLITCH Method:

Assuming you have done the High Hrothgar quest where you speak to the Graybeard and learn your first shout by taking a long 7000 step journey to to the Graybeards Monastery.  Fast travel again to High Hrothgar and enter the monastery. The Graybeards will be praying and will not give you any attention so, seize this opportunity and click the L3 button and go into Stealth mode. 

Note: Skyrim Stealth mode is essentially an eye. If you are perfectly hidden, there will be nothing but a straight line on the screen. If however, you give yourself away a tiny bit, the eye begins to open indicating that enemies are searching for you. If the eye is completely visible it means that you have been seen.

While in Stealth mode, take out a dagger and take a swipe at the Graybeards who are busy in their prayers. As soon as you hit them, your level will begin to increase rapidly. Within the next few minutes, your level will have increased by 20 or so. Although it does become irritating and strenous to level up at the later levels, around the 80's and 90's. This is a hassle free method of getting to level 100 sneak within half an hour. A fair bit of warning though, DO NOT hit the Graybeards when they are looking at you. That will be trauma-inducing as they will not even attempt to kill you but will simply keep freezing you over and over again until you get bored and load the previous save file. 

 

LEGITIMATE Method:

If you found the above method against your principals, there is another method of levelling up your sneak. You can go to Riften and join the Thieves Guild where you will find a trainer who will be able to increase your sneak level for a fee (of course). If you don't wish to spend any money, I am afraid that you will have to do it the hard way which involves randomly sneaking around cities and houses slowly adding your level upto a hundred.

 

These are the two methods I know for levelling up Sneak. You should make sure that you use your accumulated skill points to fill the better part of the Skill Tree of Sneak. Some of them are incredibly useful, letting you zoom while using a bow and arrow and slowing down time.