Optional: If you're soaking the waffles, mix the flour and buttermilk and cover it.  Let it sit overnight.  In the morning, add the remaining ingredients to a blender, then the soaked flour, and blend until smooth.

Mix the dry ingredients in a large bowl.  Preheat your waffle iron, too.

Make a well in the center and add all the wet ingredients.

Stir the batter until smooth.  If you want blueberry (or any other fruit), stir it in now.  1 - 1.5 cups is about right.

Scoop about 1/3 cup of batter into the waffle iron for each "section."  (I have one that makes rectangles, and that's about right for each one.)  Bake for 5 minutes or until your waffle iron says it's done.  Pop them out and let them cool.