Walk into any children's section and you will meet a wall of bright covers, each one claiming to be the next modern classic. It can be genuinely hard to tell which books will earn their place on the bedroom shelf — the ones requested night after night, until the corners soften and the spine cracks. The reassuring news is that you do not need a qualification in children's literature to spot a good picture book. You need to read it aloud, look at it properly, and watch how a child responds.

Start by Reading It Aloud

Picture books are written to be heard. Before you buy, read the whole thing aloud, ideally standing up, ideally with a toddler tugging at your sleeve. If your tongue trips over a sentence in a quiet bookshop, it will trip again at seven o'clock on a wet Tuesday when you are desperate for bedtime to be over. Rhythm matters more than perfect rhyme, and a book that scans well will carry a child through the story even when they do not yet understand every word.

• A refrain they can join in with. Repetition gives a child a job to do, and a predictable line lets them feel like a reader long before they can decode print.
• Language that savours sound. Alliteration, onomatopoeia and a little playful nonsense — squelching, tramping, flibbertigibbet — build a lifelong pleasure in words.
• A natural pause before the page turn. Skilled writers build suspense into the layout, so the child is desperate to see what is coming next.

Read the Pictures as Closely as the Words

In the best picture books, the illustrations are not decoration. They are a second narrative. Look for artwork that adds something the text does not say: a cat slipping out of the door, a small character in the background pulling a face, a change in the weather that mirrors a change in mood.

Hold the book at arm's length, the way a child sees it on a lap, and ask yourself whether there is anything new to find on a fourth reading. Books that reward revisiting tend to have generous, uncluttered spreads — plenty of white space, clear focal points, and colours that do not fight each other. For babies and toddlers, strong contrast and simple shapes work best; for four- and five-year-olds, you can afford more detail and more visual jokes.

Variety matters too. A shelf made up only of one glossy digital style soon feels samey. Mix ink and watercolour, collage, linocut, photography and hand lettering, and children begin to understand that pictures are made by people, in different ways, with different intentions.

Look for Characters Who Reflect the Real World

Children are quick to notice who appears in books and who does not. A picture book does not need to be about diversity to be diverse — the most effective examples simply place a child in a wheelchair in the background of the playground, or show a family with two mums eating breakfast without comment. That quiet normality does far more work than a worthy story with a lesson bolted on.

• Everyday variety. Different skin tones, faiths, family shapes, accents and abilities, presented as ordinary rather than remarkable.
• Warm, specific detail. A sari, a hearing aid, a Sikh grandad's turban, a council estate with window boxes — specificity makes a world feel true.
• Stories where difference is not the plot. If the only interesting thing about a character is their identity, the book will not be reread.

Apply the Question Test

The best picture books leave gaps. They trust a young reader to fill them, and that is precisely what sparks conversation. Look for illustrations where a character's expression is ambiguous, or where something has clearly happened between one spread and the next.

If you can imagine asking "What do you think she's feeling?" or "Where has the dog gone?" then you have found a book that will do more than entertain. Nursery staff and Reception teachers use this technique constantly: pausing, wondering aloud, letting the child lead. Books that invite questions are the ones that get borrowed from the library again and again, and the ones children later "read" to themselves from memory, turning the pages in the right places.

Trust the Reread Test

The final verdict belongs to the child. A book that is asked for three nights running has passed. A book that is quietly returned to the shelf after one outing has not, and that is fine — not every purchase needs to be a triumph.

This is where borrowing comes into its own. Your local library, school book swaps, charity shops and jumble sales let you test dozens of titles for the price of one hardback. Once you know what a child loves, buy the keeper edition: sturdy board for babies who still chew corners, paper for older readers who can be trusted with flaps.

Build a shelf with a little of everything: a funny one, a soothing bedtime one, a counting book, a book about feelings, and one wild card you would not have chosen yourself. Rotate them every few weeks and reintroduce old favourites — a book that was too grown-up at two can become a firm friend at four. Above all, do not be sniffy about the noisy, silly, tie-in titles. A child who loves a book will read it forty times, and forty readings of anything is how a reader is made.