I made my own zippered leaders.
I looked at dozens of video's and articles and came up with own method in the end.
I purchased pillow ticking because the stripes are woven, therefore on the straight of grain. I DID NOT pre-wash the pillow ticking.
I then used the stripes as my guide to attach the zippers and attach the leaders to the poles. I attached the ticking to the poles by first drawing a horizontal line on the poles, then little strips of duct tape, then a long strip of duct tape. I double checked every step to make sure my ticking was still horizontal to the poles.
When I attach the zippers to my backing, I make sure that my backing is 100% square.
I float my batting and my top.