As a general rule, most cake recipes or mixes will work for cupcakes. Simply adjust the baking time for the smaller portion, and test by inserting a Cake Tester during baking.
Proper measuring of ingredients is key to perfectly baked cupcakes - especially when you're making them from scratch. (See our recipes here at Wilton.com) Measure liquids at eye level in standard liquid measuring cups. Measure dry ingredients by spooning into nesting measuring cups and spoons, then leveling off the top. Time the mixing carefully, beating only for the length of time and at the mixer speed specified in recipe instructions.
TIP: For best results, and moister cupcakes, use large-size eggs (about 1/4 cup each).