When I purchase a kit I always cut it out as soon as possible to make sure that there is enough fabric to make the quilt, unfortunately I then want to sew it straight away as well and have to show great restraint and put it on my list of things to do. Most of the time I cut the fabric for the top and leave cutting the binding until the top is finished, once sandwiched and quilted I then decided what width binding would look best, then cut accordingly.