At any age, good skincare starts with protecting your skin from avoidable damage, particularly sun damage, and establishing a sensible basic daily routine matching your skin type. You can further optimize it by taking into account the physiology of the forth decade of life.
Thirties is the time when physiological changes characteristic of aging begin to manifest. The levels of many hormones and growth factors begin to decline (some faster than others) metabolism and cell turnover rate begin to slow down. Your skin may have accumulated sufficient amount of damage to have some degree of visible roughness, fine lines and discolorations. It is the time to make your skin care more comprehensive.
Ensure hydration
Dryness is another problem that tends to emerge in the thirties. Even though proper hydration alone is insufficient for optimal anti-aging routine, it is needed for all other steps to work properly. See our article on moisturizing; also see skin hydration tips contributed by our visitors.
Exfoliate - if you need to
In the thirties, your epidermis (the outer skin layer) would tend to become drier and thicker than in your teens or twenties because its cells (keratinocytes) are not replaced as quickly as before. As a result, your skin may look dull and have drier, more uneven texture. If you notice these changes, periodic exfoliation may help restore a more youthful feel by removing the excess of dead keratinocytes from your skin's surface. However, it is important not to exfoliate too much. If you exfoliate to the point of chronic skin irritation, you may end up accelerating the aging of your skin. You could start with mild mechanical exfoliating agents (such as table sugar scrub); if those are insufficient and your skin still looks dull, try mild chemical exfoliants, such as alpha and beta-hydroxy acids. (See also exfoliation tips contributed by our visitors.)
Treat emerging wrinkles and fine lines
Many 30+ year-olds start noticing fine lines and emerging wrinkles. This may be a good time to start using skin care agents shown to have wrinkle reducing effects. The agents backed by the most evidence are retinoids (e.g. tretinoin a.k.a. Retin A) and vitamin C family (L-ascorbic acid and some of its derivatives). Additional agents that might help but are far less proven include lipoic acid, copper peptides, and a few others. Each has it pros and cons and may be right for some people but not for others. See our topical treatments section for further details.
Tackle deeper problems if needed
Some 30+ year-olds develop problems beyond dull skin, dryness, roughness or fine lines. The most common of such bigger problems is moderate motion wrinkles. These are relatively pronounced wrinkles that develop in the area where facial movements result in skin folding. Over the years, repeated skin folding leads to local degradation of the dermis manifesting as a wrinkle. Motion wrinkles can be dramatically improved by eliminating its cause, the folding movement of the skin. The most reliable way to achieve that is botulinum toxin (Botox) injections. In most cases, Botox dramatically improves horizontal forehead creases, scowl lines between eyebrows, crow's feet, and vertical wrinkles of your upper lip. Its usefulness for nasolabial folds (smile lines) is less clear. Botox is ineffective for wrinkles not caused by facial movement. (See our article on Botox).