If I had to give advice on the one beauty trick we should all pass down to our children, it would not be to curl your lashes (by the way, you can curl lashes after you apply mascara, just let lashes dry first and be extra gentle). It would not be “Thou Shalt Play Up Either the Eyes or the Mouth” (a very, very good rule if I say so myself). And while it’s important to keep your nails all one length and painted in a classic, not too outrageous manner, that’s really a matter of opinion (and boy do I have an opinion on that topic).
The single most important beauty trick every person should pass on to their children (boys included) is this: Wear sunscreen every single day, no matter how cloudy it is.
Most wrinkles are caused by skin damage, and even worse, most skin cancers are as well. Skin cancer rates are rising due to the holes in the ozone layer. Teaching children proper sunscreen application is on par with teaching them to brush their teeth daily or wash their hands after they use the restroom.
Remember, sunscreen must be reapplied on hot, sweaty days. And please, do not encourage your children to bake themselves in tanning sunbeds lest you don’t mind them resembling beef jerky at age 70.