You can find hundreds of recipes for crêpes online, but IMO most of them don't cut it. The ingredients are fine, but the ratios are way off and produce more of a pancake batter consistency. Crêpes are meant to be paper-thin or as paper-thin as you can make them. You can only accomplish this by having your batter flow easily and freely within a few seconds as you manipulate your pan with your wrist to cover the entire surface evenly. The longer you take, the more heat-loss your vessel will be subjected to.
In my experience I have found that a ratio of 1 :1.75 is almost perfect. So here is my recipe:
1 cup All-purpose flour
Pinch of salt
2 eggs (beaten)
1 TBS of Melted Butter
1¾ cup of Milk
Combine and refrigerate for about an hour.
Additional melted butter to coat your pan for each crêpe you make.
Heat your pan on MED/HIGH.
Brush on melted butter
Pour and twirl/swirl pan/batter to cover pan surface
Within a minute you'll see a good amount air bubbles as the batter heats/cooks (about 50%)
Turn crêpe and cook for another 30 seconds (no more). That's it.
NOTES:
Use a 9'' crêpe pan or non-stick frying pan (doesn't matter)
Have a thin spatula on hand if you can't flip them (takes practice)
NEVER use a mixture of Milk and WATER. Some recipes suggest this....it's bullcrap.
IMPORTANT:
Pay special attention to HEAT. You'll be adjusting it up and down depending on how long the pan is removed from the burner.