How do I make my own recipes?

Making your own recipes does not nessesarily mean you have to make up how much baking powder and how much flour and how much sugar is added, it just means that you use the knowledge earned by people before you to make new recipes.  I genereally use the Basic Chocolate and Basic Vanilla cupcake recipes when making my own recipes.  I go to my local grocery store and take a wild adventure into the baking section.  There I have found butterscotch morsels, toffee bits, coconut flakes, chocolate chips, white chocolate chips, all kinds of things.  And when doing this I always try to buy them to see what interesting cupcakes I can make out of them.  For example I made the butterscotch chocolate cupcakes from seeing the butterscotch morsels.  I usually take the home, then try a few of them, then I ask myself, what would this go well with?  Should this be with chocolate or vanilla?  Coconut?  Usually I have to try... a... few...guilty.
Another way to do this is to take something that isn't a cupcake, that you already know.  For example, there are these cookies that I have had.  They are chocolate with white chocolate chips and walnuts in them.  I already had some walnuts that were in my cabinet and all I needed was some white chocolate chips.  I made these using the Basic White Cholate chips and they were delicious.
As you can see making your own recipes isn't hard, all you need is some sense of adventure, creativity and to be open to failure.  See what you can make.