If there’s one piece of advice guides all over the world tell guests before a tour, it’s “Bring Sunscreen!” Whether you’re going on a beach tour or an urban hiking tour, slathering on sunscreen is an important step to ensuring your tour doesn’t end with lobster skin and sunstroke.

You may be thinking, “Not to worry, because I’m off to Ireland where it’s cloudy,” but Irish tour guides will tell you the hard reality that no place is exempt from harmful UV. So do wellness guides a favour and contribute to your body’s health by revamping your relationship with sunscreen – your skin will thank you not just in the short term (sunburns aren’t any fun, after all) but in the long term as well because exposure to ultraviolet light accounts for 90% of the symptoms of premature skin aging (ie: wrinkles) and skin cancers.

To ensure you and your family get the most out of your guided trips, we’ve put together a list of how not to apply sunscreen, as well as the most productive ways to go about the practice.

Don’t use an old bottle

One thing dairy products and sunscreen have in common is their expiration dates really do matter and they don’t fare well in warm conditions. If you’re going to take the time to rub in that pricey cream, you may as well make it worthwhile; using a sunscreen that has lost its active ingredients to age or heat exposure is like covering your body with coffee creamer – pointless. Rule of thumb: replace sunscreen after one year.

Never procrastinate

It takes your skin about half an hour to fully absorb sunscreen, so put it on early, before you even step outside.

Don’t count on your makeup’s SPF rating

Two-in-one foundations/sunscreens are better than nothing, but they don’t do the trick. Why? Firstly, we tend not to put a lot of makeup on, which means there isn’t enough quantity to cut it. You need at least a tablespoon of facial sunscreen to work effectively. and Secondly, we tend to only apply foundation once a day whereas sunscreen requires several re-applications.

Take one for the team? Nope

Though selflessness is a virtue, when it comes to protecting your own skin, you should never sacrifice for others. The adage, “You smear my back, I’ll smear yours” definitely applies here. The simple solution is to always be prepared with enough sunscreen and avoid the deadly mindset that one day in the sun without SPF protection won’t kill you. It all adds up.

Less ain’t more

OK, in certain areas less is more (jewellery, work hours, photo composition) but if you want full skin protection from harmful UV rays, the more sunscreen the merrier.

There’s no such thing as waterproof

The Food and Drug Administration in the United States no longer allows manufacturers to promote their sunscreens as waterproof because they’re not. They are, however, water-resistant for a short period of time. That means you can go swimming and exercise and the lotion may adhere a little bit longer, but it will wash off eventually. In fact, good sunscreens only work their magic for a maximum of two hours (less if you’ve been sweating and swimming), meaning your skin needs to be topped up frequently.

Don’t trust the clouds

You may not be wearing sunglasses, but that doesn’t mean UV rays aren’t cutting through haze and fog. Burns happen, whether or not you can see the sun, and the nasty truth is that UVA rays actually penetrate the skin more deeply, holding them more accountable for skin aging. You still need to slather up when it’s cloudy.

Windows aren’t barriers

Bad news: glass doesn’t block the sun’s harmful rays like you had thought, so you’re not even immune from burning while driving. Going on a  guided helicopter tour or private car tour? Slather up.

SPF 90? Don’t bother

Dolling out extra for a bottle of SPF 60 doesn’t mean you’re twice as protected as if you bought a bottle of SPF 30. Experts reassure that an SPF 30 blocks out 96% of burn-causing UVB rays, and anything above only marginally increases that percentage. No degree of SPF will block 100% of the sun’s rays; it all comes down to ongoing applications. If more gives you peace of mind, go for the SPF 60+, but know it doesn’t change how long you can be in the sun, or how often you’ll need to reapply.

Don’t sub sunscreen for clothing

Dust off those hats and shades: they’ll do what suncream can’t. To help account for the 4% of UV rays that SPF 30 creams let through, turn to protective clothing, and avoid the sun during its midday peak.

Out of sight isn’t out of mind

Don’t ignore hard-to-reach body parts; your back is just as vulnerable as your arms or legs. Not a contortionist? No problem: spray cans are made for those single-person-unfriendly areas.

Insect repellant ain’t the friend of sunscreen

Insect repellents reduce sunscreen’s SPF by around one-third, so when pairing them, turn to a higher SPF, and apply it more often.