For about 6 crepes, you'll need:
1 1/4 cup milk (soy milk isn't a good substitute because the glutens in the flour don't bind as well)
1/2 cup buckwheat flour, or whole wheat flour if you don't have it
1/2 cup white all-purpose flour
1 tblsp oil
Beat the egg and the milk together. Then add the rest of the ingredients and mix thoroughly until smooth. Set aside.
Now you can prepare whatever filling you wish.
In a pan on medium heat, add a few drizzles of oil, and 1/3 cup of the crepe batter. Swirl it around until the bottom of the pan is evenly coated. In a few minutes, when bubbles appear in the batter like below, the batter is no longer liquid, and the edges start pulling away from the pan, it's time to flip the crepe.