As Aaliyah knew, age ain’t nothing but a number. Particularly when it comes to your clothes. Entering a new decade doesn’t mean you need to bin your old wardrobe at midnight – if you’ve got a bus pass but still feel good in skinny jeans and band tees, then go you.

But it’s equally true that, as you grow up, your wardrobe can too. A man’s style is based on many things – his work, his family, the depth of his pockets – and these are constantly shifting. The things you dressed for as a student don’t hold true two decades on, so it’s smart to update what’s in your wardrobe to suit your new circumstances.

What shouldn’t concern you is what is – or isn’t – ‘age-appropriate’. Great style is about confidence, not rules; if you’re comfortable in what you wear, then it doesn’t matter how many candles were on your last birthday cake. “There’s this idea that young guys have to dress one way and middle-aged guys should dress a different way,” says Thread stylist Toby Standing. “But that’s nonsense. You should wear clothes you love and that look good on you.”

What follows, then, is not a prescriptive list of looks that will place you firmly in the camp of either mutton, or lamb. Rather, it’s a set of ideas to guide your style as you grow up, should you ever find yourself in front of your wardrobe thinking, “Is this still me?” Take as little or as much heed of them as you like. Because the best way to dress your age is to know what looks good at any age.

How to dress in your 20s

It’s a hard, fast (and unfair, to the rest of us) rule of style that the younger you are, the more you can get away with. But since this is the time when you’re working out who you are and how you want the world to see you, your wardrobe should be in flux, too. “Think about your 20s as the groundwork for what comes later,” says Toby. Nothing looks bad on you right now, so test out extremes to find out what looks best.

“Fit is especially playable with when you’re younger,” says Toby. “You’ll look good in skinny, you’ll look good in loose, so try everything to find out what you prefer.” The more you sample, the more confident you can be that when you commit to a style, you’ve made the right choice.

To make style-hopping easier on your wallet, build your wardrobe around a few versatile items that you can dress in different ways. Indigo jeans dress up with a blazer, if you’re feeling preppy, but will also support dips into streetwear (add a hoodie and bomber), workwear (try a chore jacket and boots) or even Scandi minimalism (a black overcoat and white trainers). That way, one wardrobe can feel different every day.

How to dress in your 30s

Your 30s are a decade of change; jobs get serious, relationships even more so. With marriage, mortgages and mini-mes on your mind, it’s hard to find time for your wardrobe. So you need clothes that do the work for you.

“In your 30s, quality should be your watchword,” says Toby. “Buy less, but buy better.” That youthful experimentation has hopefully resulted in you knowing what looks good on you, so take the clothes you wear most often and upgrade them. “Better fabrics, better construction and better brands will have a huge effect on how you look. You can stick to outfits you know work, but they’ll look more distinctive.”

In your 30s, cost-per-wear should guide every purchase. Disposable clothes are great when you jump trends every few months. Now, the smart choice is to buy well-made items that will last, because your style’s unlikely to shift before they wear out. “Invest in quality shoes, jeans, shirts, tailoring and outerwear,” says Toby. Spending here buys you not just good looks, but also longevity. “If a pair of boots costs twice as much but lasts four times as long, then they work out cheaper.” Twice the style, half the cost.

How to dress in your 40s

Your fifth decade is when risk-taking can backfire. There’s no reason you shouldn’t keep up with trends, but when you’ve got a few crow’s feet, edgy dressing can appear as you’re distracting from something. Like an overnight shift in hair colour from salt and pepper to all-black, suddenly adopting a uniform of skinny jeans and biker jackets just draws attention to what you’re covering up.

That’s certainly not to say that 40-year-olds should live in smart-casual. “It’s just that the extremities move a little closer to the centre,” says Toby. “Rather than trying a brand new style, now’s the time to play with things like pattern, texture and fabrication.” Updating styles and outfits you know look good on you with different details means you can take new steps, but with a safety net.

“You should be adding to your wardrobe, not recreating it,” says Toby. Those quality pieces you bought in your 30s should still be there, which means you can spend your money on things that will elevate an entire outfit by themselves, like a great pair of brogues, a cashmere jumper, or a beautiful, unstructured blazer. “You’ve got classic pieces, so everything new should build on their foundation,” says Toby. “It means you can be comfortable spending a bit more, because every addition creates five or six new outfits.”

How to dress in your 50s and up

In less enlightened times, your 50s were when a man gave style up and began to prioritise comfort over aesthetics. Well, tosh. You should be comfortable, but not in an elasticated-waist kind of way; rather, you should know exactly what suits you, which clothes and brands you like best, and have a handle on how to wear your wardrobe.

“The biggest change you can make in your 50s is to nail fit,” says Toby. “Now’s not the time to try odd new trends, but rather to make the style that works for you even more refined.” Your body shape has probably changed a touch since your 20s, so find a tape measure and find out how. Then focus on finding clothes that your new shape look its best. “If you don’t know, you can message your stylist and they’ll be able to suggest pieces that fit perfectly.”

With your dependents now (hopefully) more independent, this is also the time to add a couple of bigger ticket items that will lift everything you’ve already got; a nice watch, say, or an overcoat that does more than just keep out the cold. “You can spend that money more readily if you know that those things will add to an already excellent set of clothes,” says Toby. “They can be a finishing touch that makes everything you wear feel more luxurious.”