The art of taking a good selfie is a case of trial and error. Even Tyra Banks would have fallen foul of her angles at some point but once you learn the value of keeping your chin down it's a law of photography you never forget.
Kim Kardashian, who frequently populates her Instagram and Twitter feeds with perfectly poised selfies, has raised the stakes. A butt selfie, or 'belfie', is impressive at the best of times, but as a post-baby-body-debut it's all the more eye-catching.
Will the belfie trend catch on? Given the Kardashian effect it's highly likely that this is only the beginning. Rihanna has never been shy of the lens and it doesn't take much in an internet search to find her in various states of undress, but perhaps the whole thing received a seal of approval when Cheryl Cole joined the party with a belfie showing off her Tracy Anderson honed rear and that tattoo.
First twerking and now this; the butt, or indeed the trend for them, is reaching critical mass with stars including Nicki Minaj and Iggy Azalea capitalising on their best asset. Pert and round is what you're aiming for, much in the same way a desirable selfie shows off bone structure and facial contours.
So how do you take the perfect belfie? Cheryl gave us the straight-to-camera, slightly demure option. All you need to recreate this is to tilt your pelvis backwards and slightly squeeze your bum together. If Tracy Anderson isn't on call this will fake the kind of tone you earn with hundreds of squats.
Kim, however, gave us something altogether more technical. Note the angle, the tip-toe, the height of the camera - all of which contributed to belfie perfection. And let's face it, she did a good job to crash twitter.
Taking it in stages, find your angle first. What you're looking for is something between 45 and 80 degrees - a semi-profile if you will. Then, for an all-natural lift, put the leg closest to the camera on tip-toe. Finally, and crucially, tilt your pelvis back for extra 'junk in the trunk'.
We may be heading into the winter months when it's tempting to cover up but could there be any greater ass-piration than perfecting your very best belfie? So turn up the central heating, dig out your finest swimsuit and get practising.
Like this? You might like our ' bum blitz' workout video with Freedom2Train