Sharing make up and skincare products can put you on the fast track to skin and eye infections. In a cosmetic crunch, you can borrow some products from friends-neck creams, blusher, even powder(provided you use cotton wool to apply it, rather than someone else's sponge). It's skincare, lip and eye products, and all kinds of applicators that pose the real danger. Let's face it, most of us are notoriously lazy about brush hygiene, harbouring who-knows-what in our face-shaping tools. The majority of eye irritations are not caused by eye make-up itself, but by bacterial contaminants. Increasingly, skin care companies are becoming wary of the potential for contamination posed by in-store testers too. When you're trying on a lipstick or eye make-up product, always test on your hand, rather on your face. One additional caution: if you've been suffering from a virus, an eye flare up or a cold sore, it would be good idea to replace all make-up that's used around lips or eyes. They may contain the germs that could lead to re-infection.

Don't water down your make-up

Tempting isn't it, to water down the last of that expensive mascara/toner/skin cream, to extend it's life? Well, don't. skincare products contain water, making them susceptible to contamination by micro-organisms: bacteria, viruses and fungi including yeast. For this reason, it is vital not to water down cosmetics, as you end up changing the precise balance of preservatives designed to keep the products safe. Most cosmetics have a use-by date, even though, unlike food, it won't be stamped on the packaging. Think two or three years for your moisturiser, one or two years for foundation, and replace sun-care products annually. Pencils lasts for years, but mascara and liquid eyeliner should be updated every three to six months. When exposed to extremes of temperature, however, products can go bad sooner. So always pack cosmetics in your hand luggage, rather than consign them to the air craft hold while travelling. Be alert and use your eyes, nose and common sense to tell whether products are safe. Look for changes in colour, texture or smell, which signal that cosmetics may have been contaminated, oxidised or simply gone bad.

Watch for warning signs

Ignore skin irritation at your peril. Itching, redness, hot flashes, tingling and soreness are all signals to make you examine your skin care ritual and eliminate trouble-triggers. Which usually means products recently introduced into your regime, although reactions to long-term favourites can also arise because of the body's shifting hormone patterns. In some cases, women ignore even quite strong reactions, taking them as proof that something positive is happening. Dermatologists now believe that episodes of skin reaction-allergies and irritations-may accelerate the aging process, just as sunburn does. Sensitivity is so individual that the potential for irritation always exists. Preservatives and fragrances are frequent culprits. But if you're having problems, try switching to herbal-based treatments: not only are plant extracts less likely to cause irritation, they may actually soothe it. Look for the products that contain aloe vera( a natural healer) or soothing chamomile which helps reduce itching and redness.

To squeeze or not to squeeze

That's the most vexing question for spot and blackhead-sufferers. There's only one way to empty a pore, and that is to squeeze it. Masks, creams and lotions just won't do it. Provided skin isn't sensitive or irritated, most dermatologists agree it isn't harmful to squeeze-either by hand, or suctioning with a machine. What is important is that it be done by professional hands. At-home help is a touchier subject. The problem is that most people come in from work, drop their bags rush to the mirror and start pawing at their faces. You have to prepare the skin first, by cleansing and then warming it. Ensure hands, too, are clean. Take a piece of cotton wool and soak it in hot water, then hold it over the spot for around six seconds, repeating 5 or 6 times, before squeezing. Never try to squeeze just a red lump: unless there's a head on it, you'll just spread the infection and make matters worse. Beauty emergencies are one thing; but done on a daily basis, squeezing can damage and scar the skin.

Go easy on skin-peeling creams

Peels have taken over from dermabrasion as the skin smoothing 'miracle cure'. But strip away the extravagant claims about their ability to remove wrinkles, acne-scarring and blemishes, and what do you get? Peels range from the mild vegetable or AHA 'fruit acid' variety-widely available through salons- to intense chemical peels, usually using prescription acids. Sometimes, the peeling agent is left too long on the corner of the mouth or eyelid. And, sometimes, a person has extremely sensitive skin that should never have been peeled at all. Nobody should go for a strong peel without trying a milder version first to check for reactions; some skins react with redness, burning, swelling, flaking, itching, blistering, even whitening or darkening of the skin. Also worth remembering: since nobody knows the long- term 'anti-aging' effects of these supposedly fast fix peels, you're basically a high- tech skin care guinea pig.

Scale down on alcohol and spice

If you are prone to broken veins, think less about camouflage and more about cutting down your alcohol or curry consumption. Drinking alcohol and eating spicy foods are key factors in broken capillaries. But the fact is that some people are just more prone to broken veins than others. Someone who suffers from sinus trouble may have more problems: as the area gets congested, it swells, and blowing the nose puts pressure on capillaries. What isn't implicated: cold and heat, unless you're talking extremes for extended periods of time-exposure to Arctic-type cold conditions, or hours in direct sunlight. A normal beauty regime of hot and cold water won't damage skin.

Don't overdo oil-control

Efforts to keep skin oil-free - frequent cleansing, strong astringents-can easily backfire, making skin seem greasier. But contrary to the old wives tale you are not actually stepping up oil production. What you do to the surface of the skin can't alter sebum production, but it can irritate skin, setting up a chain reaction in which pore walls weaken and leak sebum into surrounding tissue, which then looks oilier and becomes inflamed. Alcohol or acetone, found in some toners supposedly tailor- made for oily skin, are potential irritants. The result: shine. The solution? Wash gently, refrain from rubbing, use only the gentlest freshener, and avoid abrasive sponges and exfoliants. Instead of cleaning frequently throughout the day, try oil-taming items like blotting tissues, or an occasional pat of translucent powder-it contains talc, which can absorb oil. Meanwhile, check that your oil-free moisturisres and cosmetics really are what they claim to be. Some contain oil-like synthetics that can still provoke breakouts in acne prone skin. How to tell? Dab moisturiser/sunscreen/foundation on good quality stationery; 24 hours later,hold paper up to daylight and check for oil rings.

What worked for you at 20 may not work at 30-and may be a complete disaster at 40! Yet, some women continue to go through cleansing, toning and moisturizing regimes as if on automatic pilot. Skincare needs to be reassessed at the end of each decade, at the very least. Or as soon as you notice a skin change. Hormone levels are still high in the 20s. oil and sweat glands may be even more active than during the teen years, so acne and oily skin may be an ongoing challenge. By around 30, the first signs of aging become apparent: smile and frown lines caused by dryness, sun-exposure and every day muscle movement.Since the rate of cell division and replacements falls by 50% between the ages of 35 and 80, accompanied by an increasing tendency for dead cells to cling to the surface, gentle exfoliation becomes a priority as we age. As menopause approaches, sebaceous glands shrink, which may result in dryness and flaking: all skincare products-from creamier cleansers to foundation-should "put something back". Experiment by occasionally giving skin a "holiday" from your regular regime. Introduce one new product at a time so that you can tell what works and what doesn't. Give everything a month before gauging results-unless you're experiencing irritation, in which case, quite immediately.

Don't overdose on moisturiser

Even if you've a dry skin, don't overdose on moisturiser. More isn't necessarily better, as even the driest skins rarely need moisturiser on the central T-zone of the face. It simply blocks pores and can make skin prone to breakouts. Cheeks, forehead and neck are the areas where skin is really thirsty. And although women with dry or aging skin may be tempted to sleep in a thick veil of night cream, that's a no-no too. Complexions benefit from not using any cream at night. If a cream is applied at bedtime, it should be blotted off after 10 minutes, thereby allowing skin to function as efficiently as possible. Women who first notice crepeyness or wrinkling around the eye area, meanwhile, may react by slathering on too much eye cream. Eye care products can do wonders for fine lines, but if they are oily or used too often, they can cause puffiness. Because under eye skin is very thin and has a few oil glands, heavy oils are often occlusive-causing swelling. If you wake up with tired, puffed-up eyes, switch to a gel instead.

Careful with electrolysis

Electrolysis may seem like the heaven-sent answer to a dark-haired maiden's prayer, but only in the right hands. In electrolysis, papillae below the hair root are zapped with an electrical current. Incorrectly done, this can lead to local infection or, more commonly, to scarring caused by the needle rupturing the wall of the hair follicle, which can show up particularly on dark skins. Checking to make sure that your practitioner is reputable and properly qualified is a must and, even then, take a slow approach at first. If skin registers any sign of damage-such as red marks above the follicle, a day or so after treatment-cancel your next appointment. If you do opt for electrolysis, you can help the healing process by keeping the treated area scrupulously clean, leaving it free from creams, lotions and camouflaging make-up for at least a day or two. As for at-home electrolysis - a big 'NO'. This one is best left for professionals.