"Best batter and icing?" this is all preference. I use my normal cake recipes and make them into cupcakes. I use a #20 scoop to fill a standard cupcake liner and then bake for 15-20 mins depending on the recipe. I also use the same icing i use on cakes. What type of icing you use will really depend on what you are used to and what look you're going for. There is everything from a buttercream swirl to fondant, to poured fondant, to ganache, there isn't a limit.

"what do you charge?" I charge the same per cupcake as my per serving price for cakes. I find the serving size is a little less but i have higher labor sincei have to handle each serving seperately unlike a cake when i'm handling multiple servings at the same time. So the customer is getting a little less cake per serving, but i'm covering my time by keeping the same price.