Cut the lavender in the morning when it's blooming. To dry plants flat for scrapbooking, lay the lavender between two paper towels and slip it inside the pages of a heavy book, like a dictionary, for several days.
Gather the lavender into a small bunch and tie a string around the stems to keep it together. Hang the lavender upside down somewhere dry with plenty of air flow. Wait until the lavender is completely dry before putting in a scrapbook, etc.