(NBC) - Experts say a lot of people are not as protected from the sun as they think because of some common mistakes.
Skimping on sunscreen is one of the most common mistakes.
Dermatologist Melissa Piliang says not putting on enough leaves you far more likely to get burned.
Another "sunscreen slip-up" is waiting until you're already at the pool. Putting it on ten to 15 minutes before going outside gives it a chance to absorb your skin.
The American Academy of Dermatology recommends choosing a sunscreen that is SPF 30 or higher, and pick one labeled "broad spectrum" to protect against UVA and UVB rays.
Another common slip-up is skipping the reapplication. Sunscreen should be reapplied every two hours, especially if you're swimming or sweating.
Experts say be sure to pick a type of sunscreen you will actually use. Many people prefer a spray, because it's quick and you don't need to rub it in.
Hanging onto the same bottle of sunscreen for years is another slip-up. Sunscreen is designed to remain at full strength for three years. Check the expiration date on yours and pitch it if it's expired.
Although if you're using as much as you're supposed to, your bottle won't last that long!