What goes where?

I'm sure we had a thread like this before, but I did some extensive searching and can't find it. I realize that a lot of what I'm about to ask is personal preference, but wanted to get some feedback on where you carry your cards, etc.

For me, I always carry everything in case I might need it. In my left shirt pocket, I put my book with extra cards and pens. Right shirt pocket has backup whistle and car keys.

Front left shorts pocket is empty. Front right has my yellow card.

Back right...

What goes where?