Winterising your caravan.

Hello all

As my first caravan season comes to a close and before my caravan goes into covered storage, I would appreciate it if you guys can give any advice on “Winterising” my caravan.

I have already opened all of the taps, emptied the storage hot water storage tank and toilet flush. 

Also are the “wheel/tyre savers” – the device that keeps the types round so that they do not develop any flat spots any good or are they just a gimmick?

Thanks.