Measure the length and width of the dresser surface with a tape measure.
Purchase an acrylic plastic sheet from a hardware store and have it cut it to the dimensions you measured.
Position the acrylic plastic on top of the dresser and then place any electronics or other items on top of the plastic instead of the dresser surface itself. Acrylic plastic is clear and is scratch resistant.
Place a cloth or sheet of paper towel underneath beverages to provide further protection in case the beverage spills.