Choose a firm onion and peel off the papery skin
Cut the onion in half from root end to tip
Make vertical cuts toward the root (stop before cutting through the root)
Make horizontal cuts across the onion
Slice or dice to your desired size
For rings: cut the onion crosswise into slices, then separate into rings
For wedges: cut the onion in half, then cut each half into wedges
For julienne: slice into thin planks, stack, then cut into matchsticks
For preventing tears: chill the onion, use a sharp knife, and keep cuts steady
Rinse the cut onion under cold water if desired and pat dry before cooking