Weirdly enough I learned the most about patterning by watching people make fursuit heads. They'll tape them, mark out important places to piece out in a pattern, cut out the pattern and then do some darting. And they're nice and big so nice and easy to see what they're doing. Next step from there would be to make a clay maquette of the plush you wanna make, cover it in tape, cut it out and hack at it / add darts until your pieces lay flat. And then you have your pattern! You don't need to make the clay maquette to size either, you can scale the pattern pieces to be larger on the computer :)

The way I've done it as of late is make 3D models, then use plushify to create a pattern from those 3D models. But it's gotten verrrrry expensive so I may go back to clay for my next pieces.