Iceblossom

I basically do this with my french fold bias binding. I never trim until after the binding is on the front of the quilt. Since I cut my binding at 3", I line up my half-inch mark on my seam line and then trim. Gives me a nice full binding and I never ever miss catching my back into the binding, as seems to often happen to those I know who trim first.

I think the trimming first is a viable method with thinner warm & natural type batts. Would never do it on a fluffy one.