I only know how to use Tinkercad but I find it does just what I need. It took me a couple months of designing, printing, re-designing and re-printing. Sometimes I would spend hours designing some part only to decide not to use it and go in totally different direction. But that was part of the experience, if I had done this the old way I would have spent weeks or months building something out of styrene, and wasted all that time. In Tinkercad I can try things, add parts and shapes or remove them to see how it looks before printing. I don't have any design training so for me it's trial and error. I used PLA filament, painted the parts with Dulpi-Color Automotive Primer Filler then sanded between coats until I was happy with the surface finish.
Weathering was done with Dark Slate Grey powder pigment, it was just brushed on then a clear coat was added. Which caused a major disaster. The clear coat etched the styrene windows causing them to be permanently frosted. So now you can't see the interior. I'm gonna try to remove the windows and install new ones. Some airbrushing was also done to dirty up the lower surfaces.
