True lofty.....occasionally I get a very strong onion and try to breath through my mouth. It's very hard to chop onions and concentrate on your breathing at the same time..
So...Ok, first tip... cut a cone out of the root end about third of the way up the body of the onion. Be sure to include all of the roots... not much of the onion is wasted. Next, light a couple of candles close to the area where your'e cutting... not more than 4 or 5 inches away... (It does help to put the onions in the freezer for 5 or 10 minutes before cutting).