Combine the eggs, milk and flour, and blend with a whisk until they're uniformly combined. Add a pinch of salt; it is always good no matter what you're using the crepes for, but if you're going savory, you can add ½ teaspoon (and you can replace the milk with chicken stock or water, if you wish). If you're making sweet crepes, add 1 tablespoon sugar and, if you wish, ½ teaspoon vanilla. Let the batter rest for ½ hour, uncovered at room temp (or up to 1 day, covered and refrigerated); though I rested mine only long enough to heat the pan and they were fine.
Heat your pan over medium-low heat. Add a little butter, just enough to coat the bottom. If you're using stainless steel, you can swirl a teaspoon of butter in the pan to coat the bottom to ensure it doesn't stick. Pour in just enough batter to coat the bottom as you tip and tilt the pan, about ⅓rd cup.
Allow it to cook untouched until it's set, a minute or so. Then gently turn the crepe and briefly cook the other side if you wish (I usually just cook them on one side—you can see when they're set, and they'l keep cookin). If, after cooking the crepe, you would like it to be thinner, add ¼ cup of milk or more to the batter until you've got the consistency you like. Turn them out onto a plate and hold at room temperature, covered, for up to several hours.