To make crepe batter with a hand mixer, start by combining flour, sugar, and salt in a mixing bowl. In a separate bowl, whisk together eggs, milk, and melted butter. Slowly pour the wet ingredients into the dry ingredients while whisking constantly to prevent lumps from forming. Once the batter is smooth, let it rest in the refrigerator for about 30 minutes. When you are ready to cook the crepes, use a hand mixer on low speed to quickly mix the batter again.