Best fly box
I like a small compartment box that will fit in a shirt pocket size vest pouch. I carry about four of these and a big box that I almost never get into.
My wife got me a Wheatly box with flip top covers over each compartment, I never really have warmed up to it, and it sits at home except on expeditions where I think a billion flys will help, and still use only the small boxes. My favorite box is a small fairly hard plastic that is very thin, it has green felt in the compartment bottoms, and has small brass hinges, looks a little flimsy, but has really been good. I think it is either a Cortland or Orvis box.
The wind has blown a few flies away over the years, but not too many. More are snagged on trees or branches in the water.