Measure the edges of the walls on the top and sides of the built-in refrigerator.
Select a type of molding that coordinates with your kitchen or suits your taste -- crown molding or case molding, for example.
Cut the pieces of molding with a miter saw to fit the dimensions taken in Step 1. Cut 45-degree inward angles on each of the edges of the piece intended for the top of the area. Cut 45-degree outward angles on the ends of the side pieces that will butt up against the top piece of molding.
Run construction adhesive in a wavy line along the length of the back of the top piece of molding. Position the piece of molding on the top edge of the built-in area.
Run construction adhesive in a wavy line along the length of the back of each of the side pieces of molding. Position them on the side edges of the built-in area, butting up against the top piece of molding.
Hammer finishing nails every 6 inches, starting at the ends, into the pieces of molding.