Pearl earrings have an image problem. Somewhere along the way they became shorthand for weddings, christenings and stiff collars, which is a shame, because a good pair of pearl studs is one of the hardest-working pieces in any jewellery box. The trick is not to treat them as precious. Treat them as you would a favourite pair of gold hoops: something you reach for with jeans and a jumper on a Tuesday, not something you save for an occasion that arrives twice a decade.

Why pearls work so well with casual clothes

The reason pearls and denim get on so nicely comes down to contrast. Denim, brushed cotton and chunky knitwear are matte, textured and deliberately unfussy. Pearls bring a soft, luminous sheen that catches the light without shouting. Put the two together and something interesting happens: the pearls look less formal, and the outfit looks more considered.

Pearls also flatter almost every skin tone, because they reflect light back onto the face. If you have ever wondered why a plain white T-shirt and jeans suddenly feels pulled together, a pair of pearl studs is usually the quiet answer. Nothing else in your wardrobe does quite so much with so little.

Get the size and shape right for daytime

Most people wear pearls that are either too big or too fussy for everyday. A few practical guidelines:

• Studs: 6–8mm is the sweet spot for daytime. Anything under 5mm reads as a second piercing; anything over 10mm starts to look like evening wear.
• Drops: look for a drop that finishes just below the lobe rather than swinging near the collarbone. Short drops feel modern; long ones feel formal.
• Baroque and keshi pearls: irregular, organic shapes are your best friend for casual styling. Their uneven surface makes them read as relaxed rather than polished.
• Settings: keep the metal minimal. A plain post, a slim bezel or a simple huggie hoop works far better with a jumper than a diamond halo or a cluster of stones.

If your ears are sensitive, look for earrings with solid gold or titanium posts and backs. It costs a little more and saves a lot of misery.

Pearls with denim and a white tee

This is the easiest combination in the book and it rarely fails. A crisp white tee, mid-wash jeans and pearl studs is a complete outfit; add a blazer and you are dressed for most offices.

Two small refinements make it look deliberate rather than accidental. First, choose a metal tone that echoes something else you are wearing, whether that is a belt buckle, a watch or the zip on a boot. Second, keep the rest of your jewellery quiet. If you are wearing pearl drops, skip the pearl necklace; if you are wearing pearl studs, a fine chain or a plain signet ring is plenty. Pearls look best when they are the only pearl in the room, so to speak.

One more thing: don't match your pearls to your top too precisely. Ivory pearls against a stark white shirt can look slightly flat. Cream or pale pink pearls against white, or white pearls against oatmeal and grey, create a gentler, more interesting effect.

Knitwear, scarves and winter layers

Cream cable knit with baroque pearl drops is one of the great cold-weather combinations, and it works because the softness of the wool softens the formality of the pearl. Grey, camel, navy and oatmeal all flatter pearls beautifully; black can be striking but tends to make them look more evening than day.

The practical hazard here is snagging. Wool, mohair and loosely knitted yarns will catch on a setting, a jump ring or a rough nacre surface. Two habits will save you a lot of grief:

• Put your knitwear on before you put your earrings in, and take your earrings out before you pull anything over your head.
• If you are wearing a scarf, either tuck it so it sits below the ear or choose small studs that sit flush to the lobe, with nothing for the fibres to catch.

Pearls with simple day dresses

A cotton or linen day dress is where pearls earn their keep. With a printed dress, choose small, plain studs so you are not competing with the pattern. With a block colour dress, you can afford something more interesting: a short drop, a twisted hoop with a single pearl, or a pair of mismatched baroque studs if you like that look.

Pearls with trainers is a genuinely good combination and one worth getting comfortable with. The trainers pull the whole thing down into the everyday, which is exactly what pearls need. If you are wearing sandals or bare legs in summer, a drop earring balances the neckline nicely; if you are in a high-necked dress, keep the earrings small and let the fabric do the talking.

Looking after them so they last

Pearls are softer than they look. They are made of nacre, which scratches easily and dislikes chemicals, so treat them the way you would treat a silk shirt.

Put them on last when you are getting ready and take them off first at night. Perfume, hairspray, sunscreen and hair oil will all dull the surface over time. After wearing, wipe them gently with a soft, dry cloth, then store them in a pouch or a lined box away from metal chains and rings that could scratch them.

When buying, judge by lustre above all else: the sharpness and depth of the reflection on the surface tells you more than the size of the pearl. Check that the posts and backs feel secure, not loose or flimsy. And if you own a pearl strand as well as earrings, have it restrung with knots between each pearl every couple of years, especially if you wear it often.

Buy well, wear them with jeans, and you will wonder why you ever kept them for best.