What are the decorative techniques and rules for garnishing pies and pastries?

When garnishing pies and pastries, common decorative techniques include lattice crusts, cut-out shapes, and egg wash for a golden finish. You can also use fruit, nuts, or sugar dusting to enhance visual appeal. It's important to maintain balance, avoiding overcrowding, and to ensure that decorations complement the flavor of the filling. Additionally, consider the theme or occasion to guide your design choices.