I love to ride in oilskin coats, because if it is cold, they cut the wind attracted by a gallop! If it is raining, the coat keeps you dry. This is an amazing piece of equipment because the coat is long enough to go over your saddle, and down the side, so it traps the heat of the horse around your body. And if it gets hot, you can roll the thing up and strap it to your saddle. And if you want to take a nap under a tree, you can throw it on the ground and sleep on it!
I also ride with tools, which I strap on the outside of anything I am wearing. Nothing really unusual: a small flashlight, a multi tool that contains a hoof pick, a box cutter (with a new blade always) and a small magnifying glass that I can uses to light a fire if need. If I know I am going to do something crazy I wear a helmet. Since my wife Linda entered the final stages of dementia, I have taken to also carrying a cell phone.