Step 1 If using mixer or whisk: Combine eggs and salt in medium bowl. Gradually add flour alternately with milk, beating with electric mixer or whisking until smooth. Beat or whisk in oil.
Step 2 If using blender or food processor: Combine eggs, salt, flour, milk and oil in blender or food processor. Process until smooth, about 1 minute. Scrape down sides; process 15 seconds.
Step 3 Refrigerate batter for at least 30 minutes to allow flour to expand and air bubbles to collapse. Batter may thicken during this time. Thin batter, if necessary, by adding a little more milk or water.
Step 4 Spray 8-inch (20 cm) non-stick skillet or crêpe pan with cooking spray. Heat over medium-high heat until water droplets sizzle when sprinkled into skillet.
Step 5 Stir batter. Pour about 3 tbsp (45 mL) batter into skillet all at once. Quickly tilt and rotate skillet to coat bottom with batter.
Step 6 Cook until bottom is slightly browned, about 45 seconds. Turn crêpe over with spatula. Cook for 15 to 30 seconds on second side. Transfer to plate. Repeat with remaining batter. Add more cooking spray to skillet if crêpes start to stick.