Taste takes practice
On noticing what works, making choices, and learning to trust your own eye.
It's easy to point at something and say it has good taste. A website with generous spacing. A menu that opens just so. A room where the light seems to land in the right place.
Explaining why is harder. Making something with the same care is harder again.
I think taste starts in that gap. You notice a quality you can't quite produce yet, and it bothers you enough to keep trying.

Get specific about what you like
"This feels good" is a useful first reaction. Stay with it for another minute.
Is the page calm because of its colors, or because only one thing is asking for your attention? Does the animation help you follow what happened? Would the layout still work with a title twice as long?
Those questions turn admiration into something you can use. You can borrow a spacing decision and understand what it does. Copy the whole page and you might miss the reason any of it worked.
A folder full of screenshots only gets you so far. Try rebuilding one small detail. The moment you have to choose a duration or fit real text into a row, you discover how much the screenshot left out.
Make something you can disagree with
An idea can stay perfect while it's in your head. Put it on a screen and it starts making demands.
The type you liked feels cramped. The transition looks lovely once and irritating the tenth time. A quiet gray becomes difficult to read in daylight. Now you have something useful to respond to.
Make another version. Put them side by side. Change one thing at a time so you can tell which choice made the difference. Sometimes the first version was better. Keep it.
This is the part of taste I trust most, the ability to look at something you made and admit that a piece of it isn't working. Even when that piece took the longest.

Use it after the novelty wears off
A polished demo can hide an awkward tool. The demo has the right amount of content, a cooperative network, and a cursor that already knows where to go.
Use the thing with a keyboard. Give it an empty state. Try a long name on a small screen. Repeat the ordinary task until you stop paying attention to the presentation.
Does it still help? Can you tell what happened? Can you recover from a mistake without starting over?
For an interface, those answers belong in any conversation about taste. A faint label may look elegant in a screenshot and still be the wrong choice. A little sound may make an action clearer, then become exhausting when it plays on every click. Care includes deciding how often someone has to experience your decision.
Leave room for someone else's taste
I like quiet interfaces. That preference makes sense for this site, where the main job is to read and explore at your own pace.
It would be a strange rule to impose on every project. A music festival should get to be loud. A dense tool can earn its density. A playful detail can be worth keeping because it makes someone smile.
Having preferences is useful. Being able to explain when they stop helping is useful too. Otherwise, taste becomes a set of habits you defend long after the work has changed.
There will also be choices you can't fully explain. Keep some of those. An interface doesn't need a written justification for every bit of personality. It does need to work for the person using it.
Give your eye another chance

Stare at a page long enough and almost anything starts to look normal. Leave it alone for a while. Come back and read it from the beginning, without opening the editor.
The sentence you keep skipping is probably too long. The element you keep noticing may be taking more attention than it deserves. Fix the thing that bothers you first. Then look again.
That's a practice you can repeat on a small project, with ordinary tools, before anyone is watching. Notice a detail. Make a choice. Live with the result long enough to find out whether you still like it.
Eventually, you have a body of decisions you can learn from. Your next choice has a little more behind it.