Timothy, I can only tell you what I do, and have been taught.

I have kept my plane outside in some of the worst winter weather up here in northern Alberta, Canada. Temperatures can easily drop to -36 degrees Celsius. I have a full set of covers, including an insulated padded cowling cover, intake plugs, full wing covers, full stabilizer covers and full all-raound cabin window cover. The wing and stabilizer covers are padded on the inside, with special felt strips that fit over the leading and trailing edges. These covers have adjustable nylon straps to fit them snugly/tight over the wings and stabilizers,like a second skin. This is very important - you need a tight/snug fit to avoid damage to your paint.

The cabin window cover has a silk sheet on the inside, so that the windows are not scratched. The manufacturer also suggests as tight a fit as possible.

As far as tie-downs go, I am using 1' wide tape like nylon motorbike tie-downs, the adjustable type, and have been taught NOT to tie the plane down too tight, but just enough so that it does not dance in the wind. The reason is two-fold: (1) Theoretically, you can add stress to the wingspar in severe gusts, and (2) you do not allow the plane to vane a bit into the wind and protect itself in a sense by doing so. My instructor always said: "Guitar strings are meant for guitars, not planes. you don't want to make howling pre-historic music with it, you just want it to stay where you last put it."

In my neck of the woods, pre-heat is a must. I use the Tanis system, which heats each cylinder head induvidually. It also has a battery heater and an oil sump heater. If you are lazy like I am, you can also install a pager which allows you to literally just 'phone' the plane an hour or so ahead of your planned departure, and you will have a nice and toasty machine waiting for you at the airport.

Hope this helps.
Jakes