Why melt the butter: Melt the butter in the microwave for about 30 to 40 seconds until it's almost entirely melted but not hot. I find that if you just use softened butter the cookies will not spread enough, this way melted butter will give you the perfect cookie every time.
Dough too sticky: If you find that the dough is too sticky, add a little bit more flour. You should be able to form it into a ball with your hands but still easy to handle.
How do I store them: Store them in an airtight container, and they will stay soft and chewy for about 2 to 3 weeks at room temperature. You can also freeze them in an airtight container, or wrap them in individually, then place them in an airtight container.