The 5 biggest design mistakes I have made in the last 20 years of decorating and renovating – and what I have learned from them

Decorating regrets? I've had a few. Well, many. The trouble with working for interiors magazines for over 20 years is that you start to get ideas above your station – seeing some of the world's most beautiful homes and thinking, 'I could do that.'

Except I can't, not without plenty of help anyway. Because for most of those beautiful homes, there is an alchemy that comes from the trained eye of a skilled designer, and the look can't just be copied, especially when you don't have the budget, as I didn't when I first started in the world of interior design.

So these are the memorable, and easily avoidable, decorating mistakes I've made from half a lifetime of decorating and renovating, and the lessons I've learned from them the hard way, so you don't have to.

1. Following furniture trends too quickly

Perhaps the first decor mistake I ever made. In the early days of my career, ottomans and chests were big news as coffee tables. They were like central islands that designers were using to do all the coffee table styling – books, vases, trays, objets, etc.

They seemed grown-up and sophisticated. So on a trip to IKEA I bought a – now discontinued – solid wood-effect dark-stained coffee table, a great hulking thing that sucked all the light and air out of my living room.

It had cost around $150, so I kept it for ages, hating the way it was practically vampiric to any sense of space in the room. Too dark, too solid, I eventually took great joy in hacking it to pieces and sending it on its way, to be replaced by a table with slender, mid-century legs. It has the same surface area, but boy, did it take up so much less energy. And it's a shape I've stuck to ever since.

I guess this is also a wider lesson – don't follow furniture trends too closely. Invest in pieces you love and work in your space, rather than just what feels trendy at the time.

2. Not calling in the professionals

Another early career mistake – thinking I could wallpaper a room. There was a print that was very popular around 2005, created by the legendary designer Barbara Hulanicki and manufactured into a graphically patterned wallpaper.

I had to have it in my entryway, a small space that only really needed two and a half panels of the stuff. I couldn't afford a professional, but in a space that small, what could go wrong?

Now, this was a few years before YouTube existed, but I'm not sure even a helpful video would have made me any more handy. I got the wallpaper to stick to the wall, but to line up? To not peel off, constantly, at the corners, no matter how much paste I kept adding? That part was less successful.

A for effort, less than an F for execution.

3. Color drenching the walls but not the ceiling

A year or so into my career, I went to style a house shoot, and the whole house was smart, slick, sophisticated. I was lured by how adult all the shiny surfaces and hard edges were (this was 2006, remember. A different time).

The bedroom was color-drenched – back when we didn't know what the drenching trend was – in a deep, royal purple, the color of velvet, of Prince, of pure and beguiling opulence. Of course, I came home and copied it exactly.

Except not exactly. I left the ceiling white, because that was what I thought you had to do. Statement ceilings hadn't been invented back in these decor dark ages. And every night I'd lie in bed loving the richness of the walls and hating the starkness of the ceiling, and not being able to put my finger on why.

Since then, I've learned that you shouldn't always paint your ceiling white, instead pick a color for the ceiling that doesn't match the walls, but complements it. A dark brown wall with a light beige ceiling, which I now have in my den and is perfect (see, lessons learned). A blush pink wall with a deep crimson ceiling? Chic. Because they relate to each other. A white ceiling relates to nothing, unless you have white walls, of course.

4. Ordering paints thinking they would look the same as online

I knew I wanted Jitney by Farrow & Ball for my dining room color. It's the perfect shade, a warm beige paint with notes of caramel and sand, that catches the light and softens or sharpens depending on the time of day. Every single skin tone looks amazing in front of it.

But I was shoulder deep in a renovation and didn't have Farrow & Ball-amounts of money at the time, heading to a budget brand's website, picking the shade that looked most similar, and thinking it would do. The decorators were coming back in two days' time, and we'd been so busy with other parts of the project we'd not had time to get it before.

And guess what? The paint, when it was put on the walls, took on a dark, olive tone. It was green-tinged with brown, it was rich, and it was moody. I didn't hate it, but it could not have been further from the soft, soothing Jitney I wanted originally.

I've gone on to have Jitney in three other rooms in my home, used in different ways, and I love it each time. And each time I look at the dining room, I think I really wish I'd splashed the cash.

5. Thinking all tiles are made for the same thing

This was a painful one. Primarily because it was pretty recent, and I should have known better. It sounds so obvious, to say it now. But not all tiles are created equal, and not all can be used for every surface.

Let me explain. We have a small powder room that I wanted to make a big statement in, and I'd been seeing a lot of checkerboard tile ideas in a lot of very high-end schemes. It was a perfect pattern, I thought, to take up the walls and onto the window ledge. So I ordered some blue and off-white checkerboard tiles and booked the professional to come and lay them.

Except when he arrived, he took one look at my thick cement floor tiles and asked if I really thought they'd go on the wall? That not only would they encroach on the tiny room with their depth of half an inch, they'd also be so heavy they'd probably fall off. He continued to tell me that they were made this robust because they were intended to be walked on.

Sigh. I still have them sitting in a pile of boxes, waiting for me to find the perfect small floor to cover with them.

I could have gone on with this list with design mistakes I have made over the last 20 years, but these felt the most useful. These are the less silly ones that I feel like I actually learnt something from. But the key takeaway from most of the design mistakes I make is to take your time, don't get swept away by certain looks or trends or spaces you have been inspired by, and always do your research.