In a small bowl, whisk egg white until frothy. Using a paintbrush, brush egg white onto flowers and berries just until wet. Sprinkle with sugar. Place on a wire rack to let dry. Store in an airtight container at room temperature until ready to use.
Notes
You can use only berries or only flowers, if you prefer.
Recipe by Bake from Scratch at https://bakefromscratch.com/berry-buttermilk-cake-mascarpone-creme-fraiche/