Thou shalt mind your privacy settings
Repeat after me: password protection. If you lose your phone and don’t have a passcode, that homeless man who finds it on the subway platform is in for a real surprise. Also, turn off your iMessage previews. Random pictures are all-things-yes, but when you’re at mom’s house and an unsolicited pic of Mike’s crown jewels pops up on your home screen, have fun making awkward dinner convo.
Thou shalt delete all evidence
You should really delete a racy pic from your phone immediately -- sent or received. But if you live life on the edge, just don’t let your friends or grandmother scroll through your pictures. And always, always, ALWAYS keep the first photo on your camera roll PG. If you have a few hall-of-famer photos you want to hang on to, store them in Private Photo Vault, an app that requires a password for viewing. For the rest of you, take a long, hard look (lol) at your photos of nether-region naughty bits, then delete all traces from your texts, camera roll, and "Recently Deleted" folder. Or, just don’t send a photo of your penis at all. Because, newsflash: women generally don’t find them hot.