Combine oil and eggs in bowl and beat until light and frothy. Beat in milk or water, then beat in flour and optional salt until well blended. Pour batter into a pitcher, cover and refrigerate for 10 to 15 minutes, until flour absorbs liquid and thickens. Place an 8 or 9 inch pan over medium heat. Dip a paper towel into some vegetable oil and lightly grease pan. When it is very hot, quickly pour batter into pan, swirl very quickly to cover entire surface and rapidly back excess into pitcher. Shake crepe on to clean tea or paper towel. Cover with plastic wrap or damp towel until ready to use. To freeze: Place wax paper between layers. Wrap well in foil.