I recommend putting everything in a blender and blending it until well combined. I you prefer not to use a blender, you can beat eggs in a large bowl, adding water, milk, butter and salt. Add flour and keep beating until smooth.

In a nonstick skillet (I am using an 8 inch, 20cm skillet), melt a small piece of butter over medium heat. Pour 3 tablespoons of batter into the center of the skillet. (The amount of batter to make a thin crepe in 8 inch skillet is around 3 tablespoons, just use a small ladle to pour it). Lift and tilt the pan to coat the bottom evenly. When top starts to look dry, turn crepe using a thin spatula and cook the other side for 20-30 seconds more. Repeat the same process with all the remaining batter. Use some butter to coat the skillet each time. Make sure you don't stack hot crepes on top of each other.