Chop the clove
Place a peeled garlic clove with the flattest side down on a cutting board. Get out a sharp knife. Depending on the recipe, you can cut your garlic in the following sizes:
Chopped: This is the largest cut. Use a sharp knife to slice the clove through the middle. Cut garlic pieces once again.
Diced: Chop garlic pieces, then cut again to make smaller.
Slivers: Use a sharp knife to slice the clove lengthways. Take thin garlic slices, stack them and cut them again into slivers.
Minced: This is the smallest cut. Cut garlic into slivers then position your knife to cut the slivers into smaller pieces.
Whatever the size of garlic you need, to get the best results, make sure all of the pieces are roughly the same size so they'll cook evenly.