People who fill out an application as an afterthought.
About two weeks ago, I served a table and as I handed them their check and told them to pay up front, she asked me "Are you guys hiring?" I was a little taken aback because a) it seemingly came out of nowhere and b) why would you ask your waitress? Why not the manager-type who will take your cash before you leave?
Then a few days ago, I took a to-go over the phone. Young girl comes in and tells me she had ordered, so I go into the kitchen to check it's status. As I come out with the boxes, she's sitting at the counter filling out an application.
I feel like if you want to apply and be hired, you should come in of your own accord, with the sole purpose of filling out an application, not just 'Oh... well, I'm here and I guess I could use a job.."
The good thing is, they appear to want to leave a good impression and leave great tips.