Mix liquids first including melted butter or oil.
Add flour last.
If wisking or blending by hand then mix for 3 minutes until smooth. If making in blender or food processor mix for 1 minute on high speed.
Stop and scrape down sides.
Blend smooth, 30 seconds to 1 minute
Use batter immediately if made in processor or blender, let rest for 1 hour if hand mixed. Use within 24 hours.