Wallet goes in right front pocket. Phone goes in left front pocket. Keys goes with wallet.

Exception: When I'm out running, if cell phones are forbidden (certain locations at certain customers), or if I wear a suit (things like weddings, funerals and when I celebrate 17th of May.)

If a pair of trousers cannot hold these items I don't buy them.

Sticking to these invariants makes for less frustration. Not sticking to them means frustration twice a month or so.