Hulling strawberries—removing the green stem or calyx from the top of the berry—makes them more elegant and easier to eat when served plain. It is also the first step in any recipe that uses strawberries, be it salsa or dessert.
No matter how you're eating them, you want to start with fresh, ripe berries. Try to taste berries before you buy them, since strawberries can look gorgeous, red, and shiny but taste like so much fluff. If you can't taste the berries, smell them. They should smell—you guessed it!—like strawberries. Give them a good rinse just before you're going to use them and pat them thoroughly (but gently!) dry. Now you're ready to hull.