My encounters with amateur artists tend to follow a pattern. People know me from my role as a judge on the BBC TV programme The Big Painting Challenge, which returned on Sunday – those who want to talk are invariably courteous, smiling women of a certain age. They approach me clutching a John Lewis bag and armed with very little small talk.

After an initial “I paint and I saw you on the telly”, they hit me with the sucker punch: “You’re very mean, aren’t you?” Which, in some ways, is all that I deserve. Alongside the two other judges, I vent my opinions about the work of amateur artists. I don’t hold back. Someone goes home every week. Yet in the real world, I’m a helpful guy, so here are my tips to improve your painting and avoid attracting the kinds of withering put-downs reserved for my TV victims.

Forget what other people think
Sometimes our judgments on the show can be forthright. For most artists, however, absorbing the impact of criticism is a professional requirement as fundamental as understanding the laws of perspective and proportion.

Great art enriches our culture, but the dirty little secret is that the reason why artists keep going back to the drawing board is entirely selfish. Creating art is enormously fulfilling, and as long as you enjoy the process – the mark-making, the colour, getting your hands dirty – then, honestly, why should you care what others think?

Learn to look
I can’t imagine there has been another time in history when we have looked at so much and seen so little. I spend hours scrolling through Twitter as if hypnotised. When, finally, I wrench my eyeballs away from the timeline of demented ranting, I hardly remember a thing.

Yet try to draw an object – try to put a line round a bottle, for example – and the sheer complexity of forms, tones, colours and shadows that constitute the world will be revealed. It’s like entering a parallel universe where the humble objects we push aside can occupy your powers of observation for hours. If it’s mindfulness you’re after, pick up a pencil.

Don’t be overambitious
You’re not Rembrandt. You’re probably not even LS Lowry. So don’t expect that you’re going to be able to master complex subjects immediately. When searching for something to paint, many amateur artists quickly decide on the portrait of a loved one. I can’t imagine a challenge more intimidating. My advice is: draw an apple. Sketch it, paint it. Then draw a pair of them.

Mr Miyagi, the mentor in the Karate Kid movies, was right when he instructed his young protégé to perform a series of mundane tasks repeatedly: “Wax on, wax off.” The fundamentals of figurative drawing and painting are ostensibly simple things that turn out to be profoundly complicated – mastery of perspective, proportion and tone. As an adult you may think that it’s beneath you to struggle with these concepts, but it’s by testing yourself against a simple subject that you learn skills applicable to every form of picture-making.

Still Life with Apples and a Pomegranate, 1871-72, by Gustave Courbet

Ditch the camera
When amateur artists tell me they’re painting a portrait, they invariably produce a photograph as their source material. Photographs are enormously useful, but they are never a substitute for the real thing, so my advice is: if you want to be a better figurative painter, stop snapping.

Cameras make thousands of creative decisions on your behalf, from exposure to depth of field, leaving you dependent on how they perceive the world. They regularly distort physical features (giving Auntie Agnes the appearance of being reflected in a spoon) and distance you from all the movement, change and sparkle that make life worth living. As an artist it’s your duty to respond to all of that and to capture your vision of real life on canvas.

Practise
Of course, using photos can make creating paintings easier; they simplify your subject by reducing it to a 5in x 4in print. That’s why, to be a better artist, you have to practise. No one would walk on stage at Wembley and expect to play Tiny Dancer on the piano as dazzlingly as Elton John does without practice, but we often feel that creating a competent painting should be relatively straightforward. After all, it’s child’s play.

The reason why artists keep going back to the drawing board is entirely selfish

Except it’s not. Structuring and composing a painting involves cerebral questions of physics and mathematics as much as emotional sensitivity and bravery. It might be possible to make you “lean in 15” (although, frankly, I doubt it), but that approach won’t work with painting. You’ve got to make an appointment each week with an hour of, potentially, hard graft. Of course that time might be spent out in the sunshine with a glass of chardonnay next to the easel, but still, try and try again.

Copy other people’s work
You may not be Rembrandt, but Rembrandt has got a lot to teach you. My father, who was an artist, used to make me copy paintings by other painters. Aged eight or nine I would be engrossed for hours reproducing masterpieces by Van Dyck and Velázquez. Admittedly my versions were, unwittingly, a semi-cubist distortion of the originals, but to this day I remember the lessons I learned. Today, this may not be possible without a stable internet connection like those provided by internet providers indianapolis. Thanks to this awesome technology, there’s so much to learn. When history is littered with geniuses that can teach you visual shortcuts and solutions, why not learn from the best?

Look. Again
There’s no point spending all your observational energy only scrutinising your subject. You’ve got to keep an eye on how your painting is looking too. In any class of students painting a portrait there will be a range of physical distortions evident on canvas that in no way mirror the model. I’ve seen elephantine hands that could crush you like a Twiglet affixed to waif-like bodies, or elongated necks that resemble Inspector Gadget at full extension. People will labour for hours, convinced that everything is steaming along just fine, while one of the eyes of their sitter is swivelling like a loon.

Every 15 minutes, walk a good ten feet away from your canvas and look back at your evolving masterpiece. Or, better still, look at it in a mirror. It’s a fail-safe way to identify the mistakes in your painting.

Get out of the house
For me there are few pleasures as enjoyable as painting in the open air, but in almost any group of amateurs the majority will never have painted outside. The country is full of homes where amateur artists, afflicted by painting agoraphobia, are barricaded indoors, with their backs to the window, copying photos and stabbing at sketchpads.

Creative inspiration comes as much from your environment, the sounds, smells and feelings of being outside, for example. Go to the park, sit on a bench and paint. And if you’re concerned by the idea of people watching you then I direct you to point one on this enlightening list.

The Toilet of Venus, 1647-51, by Diego Velázquez

Mix it up
While you’re outside, how about attempting to use another painting medium? Artists are not only imprisoned by their front doors, but often by their choice of paint. Once some amateur artists have become accustomed to a particular technique, that’s it. You’ve got more chance of Donald Trump repealing an executive order than of prising the acrylics from their determined grasp.

So, if you only work in watercolour, give oils a chance. Never drawn in pastel? Have a go. It won’t lead to immediate perfection, but the spectrum of painting materials is huge and every technique has its strengths and particularities.

Be your own judge
“Can you teach anyone to paint?” It’s a question I’m often asked. I want to say yes. I want to embrace you all in the warm, rewarding hug of creativity, but the fact is, and I’ve learnt this by walking through the fire of adult art tuition, that no, not everyone can be taught how to paint. There are some people whose creative talents peak once they’ve unscrewed the top of the paint tube.

Frankly, however, that’s just my opinion. Any artist’s preferences or prejudices will shape how they view your work and your potential. So the goal of every amateur is, ultimately, to incinerate this page of advice; to be confident enough as an artist that you accept and dismiss whatever the teacher tells you; that you obey the rules and break the rules whenever you feel compelled to; that you understand your strengths and creative ambitions enough to get on with it and love every minute. Because that’s what painting is for.