>>385084139
disgusting
>>385084316
The pipeline these days would be buy a model from booth.pm and upload it. They are ready to upload with everything set up for basic stuff. Some models are actually free so you can get started with those.
CATS is still relevant with MMD models. Haven't tried atlasing but decimation works last time I checked.
For clothing and accessories, avatar 3.0 gets parameter driven animators for toggles. Check out some of the popular booth models if you want examples.
Physbones is pretty easy to set up. Read the documentation.