I’ve been a sunblock nut since college. At least I thought I was, until I met Jessica Yang. At work, on vacation, or while running errands, I shudder at the thought of leaving shelter without applying sunblock (unless it’s earlier than 9 a.m.).

As far as I knew, using at least SPF 30 and reapplying every two hours were the only two guidelines I had to be aware of. But properly applying sunscreen has more plot twists than a single episode of Jane the Virgin—it’s a lot more complicated (and entertaining) than you realize.

1. Your clothes can wipe off your sunblock
According to Anni Huber, the general brand manager of Nivea Men, the reason why most people need to reapply sunscreen throughout the day is because every time your skin comes into contact with cloth, the film of protection is wiped off. “For example, when people sunbathe, they apply sunscreen all over, right? But when they flip over, they should apply again because whatever they put before lying face down was wiped off by the towel,” she says.

2. If you’re staying mostly indoors, skip reapplication
I used to be paranoid about the low-level UV rays emitted by fluorescent lights in the office. Hey, ultraviolet rays mean ultraviolent skin cancer. But Jamie Sanico, senior brand manager for Nivea Body, assured me that after receiving reports of UV ray emission, manufacturers have since redesigned compact fluorescent light bulbs to make them safer.

3. You need a lot more sunblock than you thought
If you apply sunblock sparingly, you’re doing it all wrong. “There are seven areas that need to be covered whenever you’re out in the sun: face and neck, chest and belly, both arms, your back, the front of your legs, the backs of your legs, and your feet,” Jamie says. To cover each area adequately, you need about a teaspoon of sunblock.

Don’t keep measuring instruments in the bathroom? Take your sunblock and create a line from the base of your palm to the tip of your middle finger—that’s how much sunblock you need per area.

A water-based sunscreen will sink right into your skin, but isn’t safe for the beach and other outdoor activities. Lightweight formulations like Nivea UV Whitening Body Serum with SPF 25 or Vaseline Water-Based Whitening Serum with SPF 30 are my choices for everyday use. If you’re heading to the beach, it’s better to use something that’s waterproof and has a higher SPF rating, like Nivea Sun Moisturising Immediate Sun Protection Collagen Protect with SPF 50.

4. The higher your SPF, the better
There is a camp of people who insist that anything beyond SPF 30 is superfluous, but the caveat is that you have to apply sunblock correctly and in the proper amount, which is a lot more than what most people are used to.

In a recent interview with the Sydney Morning Herald, Sue Heward, the SunSmart manager at Cancer Council Victoria, advised that people who incorrectly apply SPF 30 “may not even be reaching an SPF of 10.” If you’re in a rush (or just lazy), going with a higher SPF, like Sunplay Super Block with SPF 130, could help protect you against insufficient application.

My go-to sunblock is Belo SunExpert Face with SPF 40. The consistency is crazy lightweight, and it takes no time for my skin to absorb, so I can apply the recommended amount without worrying about creating a whitish cast on my face. It’s also ideal for people with oily skin. On my eyes I use Shiseido Sun Protection Eye Cream with Broad Spectrum SPF 34. Not only does it work, but it takes forever to finish a tube.

5. Use organic sunblock when headed to the beach
In 2008, National Geographic released a study naming four commonly used ingredients in popular sunscreen brands that result in coral bleaching in low concentrations: parabens, cinnamate or octinoxate, benzophenone or oxybenzone, and 4-methylbenzylidene camphor, a camphor derivative. Because of this study, there are beaches in the Philippines that don’t allow tourists to wear sunblock unless they’re made from organic ingredients, so bring something like Human Nature SafeProtect Sunscreen with SPF 30, which is reef-friendly.

Outdoors, supplement your sun protection with the Belo SunExpert Sunbrella, which provides UPF 50. Ultraviolet Protection Factor represents the fabric’s ability to reduce UV transmissions, and the Sunbrella effectively filters out 97-percent of UV rays and actively reduces UV transmissions.

6. You may need to start using sunblock after-dark
This rule mostly applies to sun-worshippers and outdoorsy types (I can’t relate). According to studies by dermatologists at Yale university, sun damage may continue up to three hours after sun exposure. Basically, when you’re under the sun, your body produces melanin—pigments that protect your skin from damage. Once activated, however, melanin becomes “highly energized,” and form mutations that damage DNA, and eventually cause skin cancer.

While a sunscreen for nighttime use is in development, Douglas Brash, professor of therapeutic radiology and dermatology at Yale University School of Medicine, told Time that slathering on sunscreen long after being out in the sun is just as important as applying while under it.

That, and staying out of the sun as much as possible.

Photos by Jash Manuel