I winterized my boat on the 15th (last Thursday). Here is what I did:

1) Changed engine oil and filter just before haulout.
2) Drained the water heater and took it out of the fresh water system (connected input hose directly to output hose).
3) Drained my fresh water tank.
4) Put the pickup hose for the fresh water system into a gallon of non-toxic propylene glycol antifreeze and ran the system until pink came out each faucet. After that I ran the pump dry for a minute and left all the faucets open.
5) Pumped and rinsed the holding tank.
6) Pumped a gallon of non-toxic antifreeze through the head.
7) Pumped half a gallon of non-toxic antifreeze through my wash down pump.
8) After the boat was hauled disconnected the raw water hose from the raw water pump, connected a piece of hose to the pump, put the other end in a bucket containing three gallons of non-toxic antifreeze, started the engine and ran it until all the antifreeze was drawn out of the bucket and I could see antifreeze coming out the exhaust.
9) Drained the raw water filter. Reconnected the raw water hose.
10) Since I store out of the water I leave all my seacocks open. If I was staying in the water I would close them and then drain them.
11) If I had air conditioning I would run non-toxic antifreeze through the raw water side of the system.
12. I fill my fuel tank.

This sounds like a lot, but the entire process only takes about two hours with half of that time being spent on the oil and filter change.

I used 6 gallons of non-toxic antifreeze to completely winterize my boat. The procedure above has worked for me for the last 20 years here on the Maine coast where we see temperatures as low as -2F or so. I use the -50 non-toxic anti-freeze.

A couple of things I don't do are:
1) I do not put any anti-freeze in my water tanks.
2) I don't put antifreeze in my water heater.
3) I don't put any additives in my fuel.
4) I don't remove my raw water impeller.
5) I don't do anything to the engine other than winterize the raw water side and change the oil.
6) I don't change my fuel filters.