1. Have a secret question
Be wary of evil future selves or clones. If it is actually your future self, they will know the answer to the secret question; something only you would know. Like where you masturbated for the first time (in a bedroom closet.) Don’t make up a secret word (this can be figured out with future technology and “ditto” has been taken.) If your future self doesn’t remember the secret question, kill them with the really sharp knife in your boot.
2. Always carry a sharp knife in your boot.
3. Immediately ask for the winner of the 20XX Super Bowl.
Time travel will not cheap and the only way you are going to make enough money to travel back in time is to make a shit load of money betting on sports.[...]
The tips just get better after that. (HT: Mad Latinist via email.)