How to Press Flowers in a Book: In a book, between sheets of parchment paper or paper towel, lay flowers at the peak of their freshness. The flowers should be as dry as possible! Close the book firmly. Pile heavy books on top. Leave for 7 days- 1 month You can use these flowers in collages and potpourri baskets. If the flowers are edible, you can use them to decorate cookies or cakes!