Skipping Primer
If you would never skip your face primer, but do not take the time to prime your eyelids as well, you're doing yourself a disservice. Your eyelids need just as much prep as the rest of your face, particularly if you are gearing up for a full eye makeup look. Likewise, finding a ultra-hydrating eye primer is crucial.
Without a primer, there's a good chance that your eyeshadow will not go one smoothly. Plus, it will probably crease throughout the day, accentuating any wrinkles around your eyes. Suddenly, what started out as a fun, fresh makeup look could be aging you ten years. With that in mind, your first order of business should be finding a primer.
Although skipping primer might be the biggest faux pas, there's another one that we have to mention: going overboard with the shadow and liner. If your aim is to look younger, your best bet is to keep eye makeup minimal and flattering.
A thick swipe of black eyeliner could do the exact opposite, weighing down your eyes in a way that prematurely ages you. Instead, look out for more subtle eyeliner shades; grays and browns are both popular alternatives right now.
Along that same vein, make sure you keep your shadow choices strategic. Rather than loading on a ton of color (which will inevitably crease no matter how much primer you use), use a light hand when it comes to applying eye shadow and don't put it on haphazardly.
Instead, try sweeping the shadow upward, which can help give you the illusion of more lifted skin.