You absolutely shouldn’t put the picture in the center of the photograph except when that’s the right place to put it. The “rules” of photography are not laws etched in stone. They are suggestions, sometimes warnings, and are inevitably advisory. Except when I warn you to look around when you take a picture. Do not stand you family in front of the dumpster or trash bins. It doesn’t make a really pretty background. You can call that as much of a law you will get from me. These pictures are off-center because that’s the name of this challenge.
Other things that I’ve learned? Shooting in full and bright sunlight can make it hard to focus, tends to produce refraction and weird reflections and in portraits, results in sharp shadows that are unflattering. Shade is better and lightly overcast is best.