Okay, so as a mostly solo dev, it’s hard to do everything in a game. Namely, building. Whenever I do a solo project, I end up using free models or settling for not-so-good work. I cannot afford commissioning a builder for everything. The point is, I want to learn to build. What is the best way for me to do this? (This includes both blender and roblox studio) All help appreciated, thanks!
EDIT : Yes, I have checked yt and the devforum, but nothing is working well.
It’s just practice and time as stated on similar topics (all the answers are going to be the same here on similar posts) .
It’s just practice and trying different styles mainly. I recommend you stay away from free models and try to make your own.
Do not use free models never, thats a start.
You can do this
Youtube Tutorilas
Let your imagination create something
Thats a good starting
Practice, the more you try the better you get at it. (and as a the first time being a builder, it’s better to use free models so you can experiment with them, even better to make a test game where you would test your abilities.)
Youtube tutorials don’t help at all to be honest, it’s just looking at other peoples builds.
Learning is completely subjective, I’m personally a visual learner and YouTube tutorials helped me learn multiple building techniques and gave me an insight to how to use the CSG tools correctly when I was first learning.
Well I’m a self-taught builder and I suggest to start out with making simple builds then starting to make more detailed and big builds as you improve. I’d suggest looking at people like StarModelX who makes builds and other things like tips and tricks for building!
They helped me a lot ngl 
The best way is just to practice, like everyone else in this topic already said lol.
A great way of learning is to try different styles and build from reference images. Try to recreate what others have built, irl, in roblox, doesnt matter. Try to notice how things are made. What techniques you could use to recreate structures.
Blender is a very useful program to create complex shapes that you wouldnt be able to make in studio. I recommend to watch some tutorials on how to use the basics and honestly you are good to go. I use blender to enhance my builds. Usually, i create simple shapes and get creative with them in studio. Building is all about creativity. (The simple shapes do not apply for everything. Like trees or more detailed meshes ofc.)
Understanding builds is i think one of the most underrated parts of building. You can import a block with a wedge and call it a house, but is it pretty? No. Try to understand what makes a building look nice and try to copy that to your builds. Detailing plays a huge role in this part.
To finish, some standard rules to building:
Some plugins that are very useful:
Archimedes; very useful for creating curved structures from roblox parts.
Building tools by F3X; allows for very rapid switching between tools such as rotate, recolor, resize etc and change of increments.
Brushtool; very useful when filling up a map with models.
Good luck!
You should just try looking around in the “Model” tab and mess around and see what you can make and learn some new stuff. You could also watch building tutorials on YouTube and get feedback from the DevForum.
You should try to practicing building and it takes time and it doesn’t take a couple of hours to learn. Take your time and have fun building.
Thank you very much, this is a very well written post and its helping me a lot!
I recommend watching a few YouTube tutorials to help you learn the basics of Roblox Studio and Blender. Then, practice making a few simple objects such as a glass of water or a donut. You will eventually start to get better with time and practice. Best of luck 
Are you sure none of the topics helped you? While there are countless of threads that leave helpful information - tips/guides to get you started on learning how to build. I won’t go into details my suggestion would be start building and practicing, as those are the only ways you will learn how to build. You want to pick a style you want to dive into and learn how to build with it.
Consider finding something you enjoy making or something you find interest in. You always want to experiment with different things that you could work on, if you find the things that work best for you continue to keep developing in that workflow. Refer;