Wintering bees/kill ratio

[m and j bees]

Looking for comments on wintering bees. What steps are you taken when the time comes for winter. Do you insulate your boxes,wrap(if so with what), put inside,ect. Also what is the kill ratio do you think you are losing after winter?
I have seven hives, and planning on growing. Want to make it the most comfortable for the little darlings as much as possible.

Thanks for your comments

From Michigan

Mike