I personally don't understand why taking a picture of oneself in the mirror has become a fad. What I can understand is that the good people might do it solely because they might not find any other practical way to get a picture of themself taken, or they are curious to see why it's so popular and don't intend on doing it again; but there are always other creative methods. One thing I often do is velcro my phone (if my camera isn't at hand) to a surface (I have velcro bands, they come in handy far more often than you would think) and record video. I slowly pan up and down, left and right, so that when I review the video I can pick out the frame I like best. Obviously, I use my actual camera with a stand if available.
If you want to go a little further, I would, in almost all circumstances, also advise upping the contrast to make a photo look less crummy. Sure, all these steps take maybe two extra minutes, but I find that it's worth it. My phone doesn't even have a very good camera (not a whole lot better than yours), and with a few touch-ups they will end up looking finer than most raw images shot by a camera ten times the price.
Also, don't forget to get your camera to focus. They're extremely fiddly sometimes, but there almost always ends up being a way. I've never tried it, but there are probably apps that allow you to control the focus manually.
Not that I post pictures of myself or things of the sort for its own sake, I usually edit them into something surreal, trace them for practicing my 2D animation and whatnot.