Lost phone? Ask for it back with an incentive.
I thought of this after seeing all the Liam Neeson ones. With this one you give someone who finds your phone a way to contact you with your email, and also offer a decent reward. (You can edit the message). It will only work if you have your notifications come up on the lock screeen. Also the message should be short since won't be able to unlock the screen to see it all. (Test it) The easiest way to set this up is to have a DO ready to send an email to firstname.lastname@example.org with '#lostphone' as the subject. This way, if you lose your phone, you can hit it to send the notification. I also created one that sends a phone call, which can be sent at the same time.