I admit that the first time I did that, I wanted to violently murder them both, but that's just me.

The fastest way by far to raise sneak, is to sneak attack everyone and everything. Sneak Attacks push it up quicker than just sneaking around.

Combine it with ranged sneak attacks to train sneak and archery together. Sneak Attacks also don't care if the target is an enemy, so you can shoot deer for both sneak and archery training.