That doesn't mean a complete overhaul of your routine - depending on the state of your locks all it takes is a couple of tweaks to get them back to optimal condition.

We asked nine hair experts for their advice on what to do - and what to stop doing - to take your strands from lacklustre to lustrous.

Pick from these transformational new-hair resolutions...

1. Look after your scalp

"When it comes to hair health and growth, scalp is king," says Anabel Kingsley, trichologist at Philip Kingsley. "If you think of each hair as a flower, and your scalp as the soil supporting it, it makes complete sense to nourish and care for your scalp.

"Just like the skin on your face, your scalp benefits from weekly exfoliation. Exfoliation helps to remove dead skin cells and pesky flakes. It also encourages healthy skin cell turnover."

2. Protect properly

"Excessive use of hot styling tools is causing some of the most badly damaged and worst conditioned hair I've ever seen," says hair industry expert Rachel Southwood.

"Make it a New Year resolution to always use a thermal protecting product to shield hair from temperatures as high as 400 degrees. That intensity of direct heat on top of coloured or bleached hair can cause extreme problems, such as frizz, dryness and even breakage."

3. Don't brush too much

"Avoid excessive brushing, as this stretches the hair and will break weak or split ends," says hair stylist Charlotte Mensah.

"Try to only brush the hair once a day, and opt for a paddle brush, due to it being great for all hair types and textures - it's perfect for detangling and smoothing out long, thick, or naturally straight hair."

4. Get regular trims

"If you want to maintain a consistent hairstyle, you should keep up a regular hair trim appointment every six weeks, to keep the look constant and in good condition," recommends Pro:Voke expert stylist Lisa Laudat.

"Anything past 12 weeks is not recommended, as this is where split ends start to appear, particularly for those with fine hair that is damaged more easily."

5. Soothe split ends

"You can't actually repair damaged hair with a styling product, but you can use products with good ingredients to moisturise, and products with protein to help strengthen the hair strand and keep hair from further splitting," says Moroccanoil artistic director Kevin Hughes.

"Moroccanoil Mending Infusion has key protein-filled ingredients that help to seal split ends. When the hair is sealed, it gives the appearance of healthy, revitalised hair."

6. Pay attention to what you're putting on your hair

"Start looking at the ingredients," says celebrity hairdresser Phil Smith. "The way you would look at food or skincare, start to educate yourself on what goes into your hair products.

"Look for natural ingredients such as avocados, coconut water and shea butter. These are all great for the condition of your hair. Parabens, on the other hand, are damaging so don't buy haircare products that include these in their ingredients list." ~

7. Try an onion juice treatment

"The one thing that everyone will be applying to their hair this year is onion juice," predicts The Salon owner Neil Cornelius.

Yes, you heard that right, actual onion juice.

"Onions are very good at hair follicle nourishment and help restore lost nutrients to your scalp.

"They are rich in sulphur, which is known to minimise breakage and thinning, hey have potent anti-bacterial properties and help fight infections of the scalp. This, in turn, helps reduce hair fall, as scalp infections can cause massive loss of hair."

8. Up your protein intake

"It's no surprise that an unhealthy diet will lead to unhealthy hair, but if you want to improve your hair health this winter in the best dietary way, measure your protein," advises trichologist Sally-Ann Tarver from The Cotswold Trichology Centre.

"The amount of protein depends on your weight and activity, the easiest way to see how much you need is by calculating it using an app such as MyFitnessPal."

9. Tie your hair with care

"Stop using clips and rubber elastics to create sleek up-styles, as eventually, they can lead to an unexpected texture to your hair," says Michael Shaun Corby, global creative director for Living Proof.

"And stop putting your hair up at bedtime - allow your follicles to relax instead of being tugged on by that elastic all night. Instead, use soft cloths, scarves and fabric elastics to secure you hair to reduce breakage."