It's never too early or too late to develop better habits. Your skin is your body's first defense against the environment, and can be a mirror for what's going on on the inside. Keep it healthy and it will keep you healthy. There are a few simple habits that will make a huge difference over your lifetime.
The skin is the last organ to receive any of the water that we drink, and drinking enough of it will keep your whole body healthy. I carry around a giant bottle of water that I refill with pitcher filtered water. After first developing this habit, within a week I couldn't go anywhere without my bottle. Thirst is a sign your body is already dehydrated.
"But my skin isn't dry!" isn't a good reason to skip moisturizer. It takes less than a minute to moisturize. Depending on the product, moisturizer doesn't always add moisture to your skin. Many of them simply keep the moisture already in your skin from evaporating. They also help repair barrier function and can help a variety of conditions other than dryness.
The first places to show age are the hands, eyes, and neck. Even if you only apply sunscreen to your hands, face, and neck, it's the best way of keeping yourself looking young for as long as possible, not to mention avoiding dangerous UV rays. If you're crunching time, get a spray sunscreen.
Gentle acids, enzymes, scrubs, peels, treatments, gadgets: there are a million methods and options for exfoliation. Find the best method for both your skin type and lifestyle. As we age, the body's natural shedding process, desquamation, slows down. Fresh, new cells can take 20 days to reach the surface and fall off when we're under 20. At 60, it could take 60 or more days. This is why a child's skin heals so much faster than an adult, and scarring is less likely. Speeding up this cycle is critical to skin health.
This one isn't as easy for many people, but it's too important not to mention. Skin repairs itself as we sleep, and getting enough of it is crucial. Why do you think it's called beauty sleep? Just make sure you're washing your pillowcase often.