On our forum papermodelers.sk we have a whole thread on this issue for about 8 years (we worked on it for more than a year), where the techniques of building models are divided into categories and are described (beginners, advanced, shaping parts, painting models, etc.), unfortunately only in Slovak language, English version we haven't processed it yet.
Maybe you will find some inspiration there and there are also various questions answered (for example, wheel production, wheel strings, how make round sidewalls of tyres) and links to threads in the forum, where these techniques are described by members.
Unfortunately, the videos we made for this have been changed to private on youtube and cannot be played, we will have to make this visible to everyone.
If anyone is interested, here is the link.
Tipy a triky // Tips & Tricks - papermodelers.sk