From bad at-home dye jobs to nits and all the juicy gossip in between, hairdressers have seen it all.

And don’t think they aren’t aware of those less-than-perfect hair habits we adopt outside of the salon. Crap.

We asked celebrity hairstylists to share the eight common hair mistakes they see people making – and yes, we’re guilty of more than half.

1. Trimming your own fringe.

Do a DIY job on your hair every now and then? Step away from the scissors, please.

“Come on guys – five minutes to pop into your salon to have the first thing that people see on you, freshened up,” says Missy Veyret from Edwards and Co Alexandria.

“It is such an easy mistake to make to cut too much off or to completely ruin the shape. Treat yourself to a visit to your hairdresser.”

Depending on the work involved, fringe trims are also often free or very cheap – save yourself the hack job!

Watch: Kate Middleton’s hairstylist Richard Ward shares his top styling tips. Post continues after video.

2. Not using the right products.

“I know every person in the hair industry says it but I can’t stress enough the importance of having professional advice on the right hair care products,” says Jacky Chan, Salon Partner and Master Stylist at Oscar Oscar Salons St Kilda and Chadstone.

“Your hairdresser has been fully educated on what ingredients are in a multitude of hair products and what you should be using to treat each hair concern. You can’t complain about bad hair if you’re just picking random shampoos from grocery store aisles and hoping for the best!” (Post continues after gallery.)

3. At home hair dye.

“It’s a no-go! Keep it to the professionals,” says Veyret.

“Have a professional tell you what will work for you and your complexion. Pay good money for a long lasting service. Don’t paint your hair at home (along with painting your bathroom) with muddy hair home dyes!”

It may end up costing you more to fix as a result.

“The consequences of a bad DIY colour can be disastrous and usually require multiple salon trips to rectify,” agrees Chan.

4. Blindly following trends.

Being inspired by your fave celeb is great, but be realistic.

“The mistake I see is following trends too closely and trying to mimic celebrities – you need to take inspiration from trends but not feel you have to follow them to a T,” says ELEVEN Australia co-Creative Director and three-time Hairdresser of the Year Joey Scandizzo.

“A trend doesn’t suit everyone, you need to put your own twist on it that works for you and your face shape. That’s always going to look more fashionable than just copying someone else’s look.” (Post continues after gallery.)

5. Washing your hair too often.

Good news – you actually need to do less work.

“Definitely over-cleansing hair. In my personal opinion hair shouldn’t be washed every single day as it dehydrates it,” says Barney Martin.

“Keep it at a minimum – twice a week,” advises celebrity stylist Anthony Nader.

6. Using too much product.

Again, less is more.

“The other mistake I see is people using too much styling product. Less can be more especially when applied properly – if in doubt check with your stylist what they recommend for your hair type of the specific look you are going for,” says Martin.

Image: iStock.

7. Being boring with your locks.

8. Not looking after your hair.

...Then getting mad that it doesn't look Instagram ready everyday