You won’t be cutting very far into the strawberry.  Press it about one-quarter inch (0.6 cm) toward the center. Inserting the blade of your knife at an angle toward the center will save as much of the sweet fruit as possible. Avoid simply lopping off the top third of the strawberry.  
Find your smallest paring knife. Hold the strawberry in your left, or non-dominant hand
 Insert the tip of your paring knife at a 45-degree angle, where the top of the strawberry turns white. Slice in a circular motion around the diameter of the calyx, until your knife reaches your starting point. Remove the knife and discard the hull.