Other than when wearing dressy clothes, I tend to wear cargo style shorts or "Carpenter's" jeans/trousers in order to have the extra pockets. I guess I like to carry a lot of stuff. Typical stuff, Keys, wallet, pocket knife, change, honey baked ham, and phone typically (and I don't like to use back pockets at all)
I have several pair of these from Carhartt (denim & canvas) and this is the pocket my iPhone lives in:
Whatever hand is available. I don't have a set pocket for my phone. I'm dominantly left handed, but also use my right hand a lot.
Why does it matter? I'm a lefty and I use the right pocket. I suspect it's because I mostly hold the phone with my right hand while operating it with the left when 2 handed and just with the right when 1 handed. "Dominant" doesn't always mean "the only hand I can use". As a lefty in a righty world it pays to be able to use your right hand IMO. Lefty scissors and mice/trackballs aren't that common, for example.why is that?
Neither, I wouldn't dare EVER carry my phone in my pocket.