Okay, get near (Let's say the innkeeper in Merchant's Inn, Merchant District of Imperial City) a sneakable person, preferably someone who will not attack if they see you.
Once again, inns are the best for obvious reasons, you can hide in the shadows without having him follow you around (innkeepers don't do that for some reason) - Now, get somewhere safe and in the dark, just near enough to be able to collect Sneak points from the person.
I suggest using the shadows to his right, near the door which goes down to the basement. Now, my way of doing this is to lift my Xbox 360's right side (horizontal position) and slide my controller underneath the risen corner.
Let the Xbox rest against the controller's left joystick, and (if done correctly) you will notice your character beginning to walk aimlessly against the shadowed wall.
If your character is not walking into the wall, but elsewhere, use your right analog stick to guide him. The Xbox 360 technique is not required, it's simply the most secure thing I've found in my room at the moment. I'm sure something like tape, or even a well-tied string would suffice.
The idea is that if you can keep the joystick tilted, your character will move until the joystick is untilted. Meaning that if you wished, you could go out of sneak, lean against any wall you desired, use the technique above, go watch an episode of the Sopranos, come back and you will have leveled to an entire new tier (Journeyman, etc.) for Athletics.
Summary / "In English":
Aim character facing the corner of a wall.
Prop controller underneath Xbox, making sure left analog stick is tilted and Xbox is not hitting any other buttons that would alter the following
Your character will constantly walk into the wall, leveling up in either Sneak or Athletics (depending on standing position and nearby folk).
Go take a nap, get some sunshine, walk your dog, beat your girlfriend, come back in about 30 minutes to 3 hour's time and your character will have been leveling while you were gone.
To see if it worked, I tried this method before I went to sleep, woke up to find my character's sneak level to have been raised from Expert to Master.
This is only for lazy people; it is not advised that people new to the game take part in this procedure, as not only is it confusing, but it also takes alot away from the game (AS DOES ALL CHEATING).
Any questions? Stfu.
