skin moisturizing serum

Photo: Mladen Zivkovic/iStock

6 of 10
Smooth Lines

For a long-term fix, a serum with hyaluronic acid is your secret weapon, Czech says. The ingredient acts as a natural humectant to pull moisture into your skin, which helps plump the surface, filling in creases and marks. Layer it under your moisturizer to seal in the hydration-boosting effects.