3D Printing A good workflow for making joints? (Blender)

As a traditional artist I've been on and off sculpting in 3D software over the years, but 3D printing might actually be not a bad thing for making BJD prototypes.
I've been learning Blender for some time now. Sculpting the character isn't a problem, but I'm kind of stuck now.
At which point do you make the joints? I watched a ton of tutorials on how to make booleans, and if you don't want to mess up your geometry, your vertices will need quite a lot of adjustments, it seems.

So it's probably a good idea to boolean early in the sulpting process, while the sculpt is still low poly?
But if so, the ball joints (3d spheres) will also have to be low poly - meaning they are not smooth spheres … and once they are part of the doll body it will be hard to sculpt them into actual balls.
How do you handle this?

i don't own a 3D printer, so I can't just test what works. I've downloaded a few STL files to look at the geometries, but they dont help … (I got a pile of books on 3D printing from the library, but they are mostly about how to set up your printer, not about decent sculpting for print)

 

I haven't found a solution yet but I've researched some more. It seems you can just boolean the fairly high poly objects and then smooth out the edges with dyntopo turned on.
It would definitely help me to have some of my sculpted pieces printed. The only 3D prints I've held in my hands were made by a low quality printer and looked like they had been sculpted with a glue gun …

 

The printing services in my area are pricey and more aimed at architects and engineers - but a distant friend has just offered to make a test print for me. So maybe I'll be able to answer my own question soon …

 

Finally … Working with Blender for 3D printing proved to be quite uncomplicated. I used the the Bool Tool and the Print3D plugins. Blender 2.81 also has a new Remesh option which helps with topology. I had to repair a few vertices, but it didn't take long.
Getting decent prints from from your 3D files is a lot of trial and error, calibrating, regulating temperature and speed though. It will take some time experimenting with settings and materials, but all in all I'm quite happy with my results so far.

 

@nattherat Thanks for your recommendation, I've watched a lot of reviews, and the Flash Forge Finder was one of the printers on my "wish list". In the end I got the Biqu Magician a couple of days ago. It's very small which is okay for the parts I want to print, and offers a great quality for a budget printer. I'm currently experimenting and having a lot of fun!
Printers have improved a lot since I attended a 3D print workshop a couple of years ago. I'm the experimenting type of artist and like to work with iterations and alternatives of the same model - I'm so happy to be able to print prototypes in eco-friendly PLA now and not waste a ton of toxic materials on parts that don't work out.