I do not like those really wide bindings, so use 1 1/2 inch with a 1/4 seam allowance. Start a few inches down from one corner applying the binding facing the quilt(be sure to turn under the raw edge on the starting end about 1/2-1 inch), so when you get done attaching it, turn the binding over, then turn the edge under, pin and I then hand sew it. If you are using a higher loft you will probably have to increase the width of binding. I use low loft on all my quilts.
IdahoSandy