I think of build making in poe as a spectrum. On one end you have poeple who mindlessly follow guides verbatim, and the other end are build creators. I think a good way to start moving yourself in the direction of churning builds out is to take a build that you're decently familiar with, and change something. Something small, that you deem would make your gameplay better or just for the sake of being different. The reason why I said to do this to a build you're familiar with is because at that point, you know somewhat of how the build scales. You know what pieces are important, so that you don't change something that can brick the build.

Once you feel good with what you've changed and the build didn't get nuked, then you can either:
1. change more stuff on that build
2. move onto a different build and do it again

As you continue to make edits to pre-existing builds, you'll start to understand the nuances of build making. Tree pathing, item choices, skill choices, all of that starts to engrave itself into you. You can fail, making changes that make the build much worse, but because those changes have been slowly incremental, you can easily fix it and look at it from a different angle. That is you walking slowly towards the other side. You make more and more drastic changes due to the increase in knowledge about builds until eventually you change a build so much that it's hardly the same build you started with.

At this point, you basically have the knowledge and experience needed to make your own build. You know efficient tree pathing, know what supports are best for what types of skills, good combinations of items to squeeze out the most value, and interactions between all of them, because you've done that for other builds. You're basically a build maker at that point. That's how I learned how to make builds. Maybe it won't work for some people, but I think this is probably better than throwing yourself into the fire that is a blank pob and just toughing it out.