Squeeze the lemon to extract the juice. Collect about 1 tablespoon of lemon juice. This gives you a 2:1 ratio of oil to acid. If you like your salad dressings more acidic, squeeze 2 tablespoons of lemon juice from the lemon for a 1:1 ratio of oil to acid. Add the lemon juice to your glass jar.
Peel your garlic cloves. Squeeze the cloves of garlic through the garlic press. Add the garlic pulp to the lemon juice.
Add salt and pepper to your lemon juice and garlic mixture. Add enough salt and pepper to taste. You can add more later if it's underseasoned.