And then there's the Unhappy Snappee.

Every family has one – the person who refuses to smile for the birdie, looks sternly at the lens, or barks at anyone even attempting to include them in a picture.

How to get them involved in a happy snap or two as part of Christmas celebrations?

“The key is to relax,” according to photographer Alex Kennison from Savvy Studios.

“But some people will always be uptight and nervous in front of the camera – generally those people have had bad photos taken by friends and family all their lives and are now a bit paranoid.”

Kennison says that in that case, candid photographs will always look better than forced smiles.

“Try getting the kids to take photographs. Kids are often less threatening than adults ... and Nanna will always smile for the grandkids.”

Kennison photographs weddings, parties, anything, and has some helpful hints for both the subject and the photographer.

Tips for the subject

• Take fewer “selfies” – ie, self-portraits with your smartphone camera. Kennison says such photos are actually taken at an unflattering angle, because the phones' wide-angle lenses distort your features. “Everyone's so used to taking selfies, they're used to looking like that.” Instead, get someone to use a proper camera from a distance, and zoom in on your face for a more natural, flattering angle.

• If you can, find a close friend or family member, someone you trust, to take the photo. It will help you feel more relaxed.

• If you're worried about a double (or triple!) chin, position your body side on to the camera, then turn your head back towards it, looking slightly upwards. The movement stretches your neck and creates a more defined jawline.

• Smile with your eyes. This is crucial, according to Kennison, particularly if you worry about your teeth. “You can smile with your mouth closed and it still works, as long as you have smiling eyes.”

• If you're really nervous, try having a little drink. “People will be more inclined to smile and enjoy themselves in front of the camera with a little bit of alcohol in their system.” But that is NOT carte blanche as Kennison says things can get ugly fast. “Half the time they've got their eyes closed, or they're falling over. I've almost lost equipment.”

Tips for the photographer

• Engage the subject in banter. Try to find out things about them, or ask them to share memories or stories. Recalling details will ease their nerves, and provoke emotion, which then comes through their expression.

• Make jokes. Kennison suggests Borat impressions, or asking everybody to say "knickers!" instead of "cheese". “Bad dad jokes like that really work well.”

• Focus on the image as a whole – foreground, background, the emotion of the subject, relationships between the subjects if there are more than one – it will help the subject realise you are not focusing on their perceived physical flaws.

• It's the person who takes the photo, not the camera. If you invest in a good quality dSLR camera, put in some time learning how to use its settings. “The appreciation of the art of photography has been lost in this digital age,” says Kennison.

Toothy grins

If you don't smile because you're worried about exposing your teeth, Andrew Wong from the Australian Dental Association Queensland says it may be time to visit a dentist.

“The vast majority of dental problems are preventable,” says the Ipswich-based dentist, recommending brushing twice a day, flossing once a day, getting six-monthly check-ups and maintaining a healthy diet with limited sugar and acid.

“Keeping the levels of bacteria in the mouth low can prevent periodontal or gum disease, which reduces the body's ability to fight infection,” says Dr Wong.

Smoking not only stains your teeth yellow, but can cause oral cancers. It's another good reason to quit.

Tooth-whitening is an option to improve colour, but it's recommended to do it through a dentist to ensure the right application of chemical lighteners.

Composite fillings can be used for minor chips and cracks; composite or porcelain veneers for more severe fractures or discolourations.

“Crowns can be put over teeth to strengthen them and change their shape, but we only do that if the tooth is badly broken down,” says Dr Wong.

Orthodontics is another way of improving your smile, with the old-school metal mashers replaced with clear brackets, or even braces that attach to the inside of your teeth. Sequential aligners are a series of clear moulds that the wearer changes frequently to slowly move their teeth into a more desired position.

Dr Wong says while many remain scared of the dentist, a large number of procedures these days are relatively painless.

“It's important for you to establish what you want with your smile, and to make sure the dentist understands and can deliver that,” he says.

“And always try the most conservative treatment first.”