Most of my hunting lately is from a canoe, drifting rivers and streams.
Camo is important - I use 2 sheets of camo burlap from Walmart to cover the canoe - 1 in front of me and 1 behind since the inside of my canoe is light colored. I have matching velcro tabs along the outside gunwales to pull it tight (self-sticking fuzzy on the boat with the hook side stapled to the burlap fro a quick fit). I then put a bunch of local brush and cane on the front, poking out about 2-3 feet above and to the sides of the boat. Sit low in the boat, on a pad in the botom, not high in the seats. It looks like a big brush pile drifting down the river. Paint or tape all light spots and the paddles. You will know you have enough camo when the ducks will not fly until you are 5 yards out.
I drift along close to the bank, watching the river margins ahead, and look closely behind downed trees. I have padded the gunwales with black foam pipe insulation to lay my paddle/shotgun alternately when I spot ducks ahead. I keep an extra paddle handy since I tend to freeze when I see ducks, then let the paddle slide quietly out of my hands when I reach for my shotgun.
I see lots of woodies, plenty of mallards, and some hooded mergansers, teal, and blacks late in the season. It is a fine way to spend a morning, or an afternoon when the ducks aren't coming to your decoys, or especially when the ponds are all frozen.
I usually pick a river segment that lets me float around some big horseshoe bends and walk back a couple of miles to my truck without having to schedule a shuttle.
If you hunt with a buddy, take turns paddling, with the gunner ready in the front. If you see a real big raft of ducks, you can turn the boat sideways and both shoot (watch for broadside rocks!). I am not worried about giving away my secrets, since you will rarely ever encounter any other hunters this way. Try it, if you are a good paddler since winter is not a good time to get wet. I carry a dry bag with extra clothes, and tell someone where you plan to float. Canoe books are available for most areas that point out some good routes and access points, though most any bridge crossing will do.