> "Do you plug your nose when sucking?"
I think it's important to get a good air seal around mouth and nose when sucking in air. Think of how a respirator fits. I make a (sort of) diamond shape with my fingers that seals around nose and mouth, then pull in as much air as I can. While my nose isn't obstructed, it isn't really used, either. Air goes in the mouth much faster so the nose just hangs out and watches the show.