The world’s most popular website is called Face book for a reason. Avoid using silhouettes, pets, or babies as your main image; people want to connect with you, not a landscape.
The "High-Key Headshot" —a photo taken with natural light, facing the camera, with a clean background—is the most versatile and successful format for 90% of users. It works for friends, family, and colleagues simultaneously. for facebook profile picture
Soft, natural daylight from a window is much more flattering than harsh indoor bulbs, which can create unflattering shadows on your face. Technical Requirements and Sizes The world’s most popular website is called Face