Any ongoing comic or animation series needs to set standards, in order to keep consistency over time. Sure, the very earliest Simpsons cartoons are different from what you are used to, but after the first couple of years, they've pretty much remain unchanged for three decades. That's because there are rules.
If you've wanted to make your own Rick and Morty drawings, but can't seen to get it just right, maybe you need some guidance. There's plenty of it, in notes from designer Maximus J. Pauson and co-creator Justin Roiland. They have apparently made all these mistakes in the past so that you don't have to. See more of these Rick and Morty drawing guides at Cracked.
(Image source: Character Design References)