I'm looking for money, phones, watches, rings. Things I can easily hide in my pocket. And there's plenty of opportunity. I see lots of bags and purses left on desks with no one in the room. Maybe they've nipped to the toilet or for a natter with a friend.
Some people make it really easy.
They leave their keys in the door lock. Two and half seconds. That's a good one. I leave the things I can't use somewhere they won't be found for ages. A decent computer or a video might go in some bushes nearby, then I wait until it is dark and come back for it.