A basic way to cook clams is by steaming them. First melt a couple tablespoons of butter in a saucepan and add chopped garlic, then stir and let cook until the garlic is softened. Add in the clams, just enough to cover the bottom of the pan. If they overlap, the ones at the bottom may not open due to the weight of the clams on top. Stir to get the clams coated in the garlic butter.
Add about 1/4 cup of white wine per dozen clams. This creates steam to cook the clams. Cover with a lid, making sure the lid is not touching the clams, and let steam for about 4 minutes. Do not touch the lid until then to avoid releasing the steam.
The clams should now be open and ready to eat. If not, put the lid back on and cook until the clams are opened. Add a splash of lemon juice if desired, or a sprinkling of fresh herbs, and serve.