It all begins by picking a good onion. Find one with smooth skins, no blemishes, and no soft spots.
You will want to use a large, smooth edged, chef's knife any time you are cutting onions.
Start with cutting off both the root and the stem ends.
Turn the root end up (it has that darker spot there) and slice in half.
Now, it's really easy to peel off the outer layer.
Slice each half, one at a time, from the stem end to the root end. The root end should help keep the rings tight together. If they do start to come apart towards the end and you think the knife may slip; it's far better to discard the end than risk cutting yourself.