How do you sneak up on someone in Hitman 2?

Heh, apparently the L1 button has two different functionalities. I thought sneaking required you to hold the L1 button down (nothing in the game ever said otherwise, and most other games I've played require you to hold the button), but holding the button down actually causes you to crouch rather than sneak.

What you actually have to do is just press the L1 button (releasing rather than holding) and you enter into sneaking mode, and you press L1 again to exit out of sneaking mode. While in sneaking mode you are able to sneak up behind people and perform the sneak attacks (like I have been informed is possible).

Using this method I have not encountered any problems with successfully completing the sneak attacks.