ITA w/quirky, an unpadded ring sling is going to work the best. IMO it's the best for nursing in general, but especially in the football hold. i've done it many, many times. if not a ring sling, a rebozo in a one-shouldered carry is pretty much the same thing, though i find it easier to adjust the rings than a slip knot, it's more or less the same basic idea. or if you wanted the ability to have both a rs and a rebozo, you can get a rebozo and a set of sling rings from slingrings.com and use the rings as a no-sew ring sling (there are instructions on Jan Andrea's sleepingbaby.net website, it's super easy).
if you know how to work a sewing machine, making a ring sling is about the easiest sewing project in the world. directions for that are also on Jan Andrea's website.
good instructions for tying a rebozo slip-knot can be found in a quick youtube search.
