M.I.T. graduate Aditya Khosla recently published What Makes an Image Popular?, a study seeking the keys to image popularity (sweet validation!). While Khosla's findings aren't tips per se, they do offer insight into what distinguishes stellar images from basic lunchtime offerings and empty landscapes.
The first thing to do is to go red. Khosla's research found that reddish hues are known to make onlookers stop longer than cooler tones. Khosla also stresses to take pictures of what you're drinking, because drinks are the most surefire way toward a true, authentic self (right?).
The rest of the research stresses the importance of bras, revolvers, geo-tagging, and busy compositions. According to Khosla, the busier the image, the more successful it performs. (Take that, minimalists!)
However, these are merely guidelines for Insta-fame. Virality, like safety, is not guaranteed. (Complex)