This is the answer: do a lot and a lot of modeling and simulation.
have you guys watch the amazing spiderman yet? at first i don't want to because spiderman from toby is great. then i just try it and got me thinking that spiderman is a happy hero and very athletic, so this new film is more suitable to be called spiderman, only a few character development is at missing, like how is not open to his girlfriend. overall, it is very entertaining and awesome.
i am very amaze to the technology today that we have, we can make any impossible visual that very imaginative to our eye and brain. thanks to the power of computer graphic. that's why james cameron wait for several years before making his avatar film.
i found this very great video about what is it about being a Computer Graphic Artist and Visual Effect Artist do, this video really explaining it well.