Cooks Illustrated suggests the following to speed up your onion prep work. First cut off the root end, halve the onion from pole to pole, and then peel it. Place the onion halves flat side down on a cutting board and cut into 1/4-inch slices across the grain.
If you love onions so much they bring tears to your eyes, try lighting a small candle and placing it next to your cutting board. The flame will burn off some of the gases that make you tear up; or alternatively, try storing your onions in the refrigerator. Cold onions don't produce as many tears as room