The very beginning of my routine starts with only paddling water I know and only going out with paddlers with whom I am familiar. I do not want any surprises when the water is cold.
The second part of my routine is to assume that I will spill and get wet, so I bring safety materials to treat a wet, cold person. That usually includes a thermos full of hot tea, high carb snacks (like a crunchy granola bar), a spare set of fleece clothes, a spare paddle jacket, fire starting material, and one of those space blanket things. All of it fits into one dry bag.
The third part is what I wear. My outer wear is the most important. I have a semi-dry top (the neck gasket is neoprene, otherwise it has latex cuffs and a tunnel hull waist) and I wear it with waist high waders with a wide neoprene waist that fits in the tunnel hull of the semi-dry top. VERY little water will get in even in a submersion and I can still swim in it. It's clumsy, but I can swim in it. The outermost layer of course is my PFD, which goes on while I'm standing on the bank at the put-in and doesn't come off until I am standing on the truck at the take-out. As far as what goes under the semi-drytop and waders depends on a lot of factors. There's enough room for me to wear a wicking layer and a thick fleece or wools sweater on top, and I usually wear fleece wader pants on the bottom, sometimes with a wicking layer as well. For a hat, I usually wear a ball cap or a wool watch cap.
Pretty routine stuff for me.
Shoes are usually flats boots - zippered neoprene socks with a thin rubber sole - that are over-sized to fit over the neoprene socks built into the waders.
- Big D