Winterizing Diesel 28 (No Genny)

[Bullish]

My second year performing the winterization myself. Besides inhibiting the freshwater cooling system, other freshwater systems and pumps, adding winterization agent to the fuel and topping off the tank, and changing oil, is there anything else that you recommend?

I know some boaters remove the impeller and loosen the belts too.

Also, what is the best product to add to the fuel for winterization?