To my mind, one of the important aspects is that code must be easy to understand, so as to write it correctly.

Every virtue is easy to argue for in isolation. All else being equal, who wouldn't prefer their code to be easy to read? Or easy to extend, performant, simple, small, secure, packed with features, well tested, and so on.

The trick is that writing code thats easy to understand often takes more time. Making code performant will often make it harder to read, and harder to change. Adding lots of features will make your code harder to change.

Its easy to point at the virtues of good code. And its easy to pick out some personal favorites. But the difference between an intermediate and expert programmer is knowing how (and when) to trade those values off against each other. When you're prototyping, write messy code that you can change easily. When you're writing a web browser, agility doesn't matter as much as security and performance. If lives depend on your code (eg in medical, rocketry, etc) then testing becomes a lot more important. Working with a lot of junior engineers? Try and write code they can understand and maintain more easily. And so on.

Its a fine thing to have a personal style when programming. But the mark of excellence is whether you can adapt your style to suit the actual problem you're trying to solve.

I like the idea of thinking about various code components as furniture!

In practice you can get by with a wild collection if non-matching furniture. It will be non-asthetic but it will work.

Code projects are quite similar in that regard. On the other hand sometimes it will be such a poor fit that it starts breaking things. Does that also apply to furniture?

Perhaps if you put the bed too close to the closet you can no longer open its door all the way...

There are also furniture pieces that are made to connect to each other. Some are obvious like peg boards, but things like sectional couches, too.

Then there are the myriad array of cabinet doors. And folks like heavy built-in cabinets, but Ikea ones are just fine. They typically have better hardware. But nobody wants to be the equivalent of an installer in software, it seems.

Since you said beds, consider getting the wrong size bed for a room. Or mismatched head and foot boards.