Fun ways to troll my teenager using Elf On A Shelf?

My son is 17 years old and we’ve never done Elf On A Shelf. I’m thinking about getting one this year just to mess with him. I’m looking for some help coming up with ideas to troll him with things like a note next to the elf saying to remind Santa to check my kids browser history. Looking for any good spirited obnoxious ways to make my son roll his eyes at me.