The first tip in this series about social media discusses the profile picture, specifically on Facebook. Aaron Marino of alpha m. says that your profile picture is something that everyone can see and paints a specific picture about who you are.
Your profile picture gives a broad impression of who you are. If you post something crazy or shirtless, you may want to consider taking it down. Use a picture that best represents how you want to be viewed by the outside world: would you hire, be friends or date you?