I also use the viewfinder most of the time, unless this old body won't let me get down or up to where I want the camera. Metal knees aren't near as good as the originals. I too, need a plan for getting back up, but with metal knees they took out the padding, so a thin carpet feels like kneeling on sharp road gravel. I keep a 3" foam pad in the studio for such emergencies, but still need something to climb.
In bright areas I do what the old glass plate photographers did. I have a 3' X 4' double layer black cloth that I place over my head and rear of the camera, so I can see the screen for the shots while I'm out in bright Sunlight. This cloth has a fabric strap loop attached to the center of one long edge of the cloth that's large enough in loop size to fit over my largest camera lens (70-200 mm). This allows me to hook it over the lens to help keep it in place on windy days. This cloth is Bright Sun Proof ,because of the double layers and it's very light in weight. It's made of black cotton bed sheet material, so it folds small to allow me to keep it in a zip-lock bag and stowed in my camera bag. I don't use it often, but will never be without it. Talk your wife or significant other into sewing one together for you.
Now the question about hats?
I usually wear a baseball type cap. It's usually white and of a design that is a mesh ventilated fabric (very hot Summers here) on the rear half with a Velcro size adjustment strap. Mine say "PHOTOGRAPHER" in red across the front in large letters. I had wanted it to say "Staff" on the upper line and "Photographer" below it, but the supplier left Staff off and I decided that it wasn't necessary anyway and didn't return them. When shooting begins, the hat is turned to put the brim on the back, so I can get my head close to the camera to use the viewfinder and I usually forget to turn it back after the shoot (anybody else have a half round Suntan spot on their foreheads?). I've been looking for a better hat design that works well for photographers, but I haven't found one yet. I burn easily and thin hair doesn't help much, so a hat is absolutely necessary when I'm outside. Any suggestions will be appreciated?
Charley