Thaw: Place the frozen phyllo in its packaging in the refrigerator overnight (do not thaw in the microwave). Trim: After opening the package, use kitchen shears to trim any edges that are dry or clumped together. Transfer: As you move individual sheets of phyllo, place one hand underneath them to help prevent tearing. Cover: Keep the phyllo covered with a slightly damp kitchen towel while you're working; the sheets can dry out quickly. Store: Stack leftover phyllo on a baking sheet and cover with a damp towel, then wrap tightly with plastic wrap. Store in the refrigerator for up to 3 days; do not refreeze.