You can have the best sunscreen available but it’s only as effective as the way that it’s applied.
Sunscreen of SPF 15 should be applied daily, 15-30 minutes before sun exposure. If you’re wearing make-up, it should be the last product you use in your skincare regime before applying your make-up products over the top. Many modern make-up brands contain SPF 15 or above as standard.
If you’re on holiday, or subject to prolonged sun exposure, two tablespoons of sunscreen should be enough to cover your whole body. Remember that slapping it on thick won’t offer you any more protection than 90+%, but equally, applying too little can decrease its effectiveness.
Sunscreen should ideally be applied every couple of hours to remain effective during prolonged exposure.
It’s also important not to forget that UV rays can reach you everywhere. You may think you’re safe in the shade but light bounces off every surface and can still reach you under parasols and canopies. Using sunscreen is only one way to protect your skin. Protective clothing can go a long way to deflecting UV rays. Be cautious though, closely woven, dense fabrics are key and many items (such as t-shirts) offer surprisingly low protection, sometimes as little as SPF 2.