I keep the car key and my house key in a zip-up pocket in my trousers. I used to keep my wallet (one debit card, a bit of cash) in a velcro pocket on the trouser leg but since I got a Haglof jacket with a zipped internal pocket the wallet now goes in there.
At night, I put the wallet into the foot of my sleeping bag, a security habit from attending music festivals.
I keep my mobe in a pocket (either in my gillet or in my trousers) during the day. At night, the phone goes under my pillow.
I keep a set of house keys hidden in the garden and another front door key with the neighbour who feeds the cat when we're on holiday.
Not lost anything - yet.