That isn't the easiest thing to answer, but I'll try.
-My accent's weird. My dad's British, my mum's Kiwi, and I'm Australian, and my accent kind of fluctuates between the three, or at least, it sounds different to different people. E.g. Australians will think I'm British, Brits think I'm Australian, etc. When I've heard my own voice, when I'm speaking, I'd say I sound more British, but if I hear it recorded, it sounds more Aussie. Occassionally, people have thought I'm a Kiwi, but while I can say that NZ definitely has an accent, it's hard for me to define exactly how that accent sounds in relation to others.
-If we're talking about how I speak in real life, it also varies. I mean, obviously I need to be more formal at work than elsewhere, but I guess...this is going to sound high and mighty, but I have a tendency to use phrases/expressions that aren't always to the point, or best used for people for whom English is a second language (which is extremely common where I work). More than once, I've been instructed to use more simple language. And don't get me wrong, that's a good direction given the circumstances, but basically, unless I'm talking to fellow staff members, how I have to speak at work is far different from how I usually am.
-More casual settings, far more willing to use slang, make jokes (you've probably noticed the no. of puns I've made here), make curses, etc., but I think in this area still got more 'poshness' than what we might call "bogans" here. Never been one for a "shrimp on the barbie" or any of that. That stereotype is real, and I meet a fair no. of people like that in real life, but generally, more likely to say "twat" or "bollocks" rather than more...creative curses, for instance. Far quieter, don't have any tattoos, prefer to avoid confrontation, etc. Probably also compounded by definitely being an introvert. Basically, far less direct than a lot of other people, in general. Fine talking with friends, but the friends I've kept in touch with from school are far closer to my own personality than away from it.
Make of that what you will.