If you own something that's beautiful but doesn't do its job well, then you're doing something wrong. That is not to say aesthetics have no place in daily life. You want to be surrounded by items you like and not something that looks ugly and you despise. The two aspects, Form and Function, don't have the same weight. Function should always come before form.
When it comes to objects you should also try to take into consideration what owning that specific items means, not just using it. Every object in your life comes with a set of requirements, things you need to do in order to take care of it and use it properly. Try to minimise those as well.
You want items that have a small footprint in every aspect of your life. You want clothes that don't require constant washing and ironing, you want furniture that doesn't require constant cleaning. Items should be there to serve a purpose and not be a burden.
Also, try to buy things that can serve more than one purpose, this way you can invest in a single quality object rather than owning multiple ones. That's my mindset while buying clothes: how many different things I can do with just this one item? My new pair of pants are comfortable enough to be worn at home everyday and plain enough to be worn for dinner or for a client meeting. But are also hiking pants which means I use them when I go hiking and are waterproof so are excellent in wet weather.
Combining functions is the key to a minimal lifestyle. And coincidentally, it's also the reason why I ended up wearing only a certain type of colours. it's easier to combine clothes when you only own black, grey, white, and beige clothes. Mixing becomes way harder when you have a wardrobe that resembles a rainbow.
This concept of giving function priority over form is the single most important aspect of minimalism. It's what enables you to own less because it forces you to evaluate what you need to accomplish before you purchase something new.
Giving function priority over form is the single most important aspect of minimalism
It forces you to be mindful. And when you have your "consumer priorities" straight then you can add a layer of style on top of that.
This is Chapter 3 of the Manu's Guide To Minimalism. Links to the other chapters are down below.