this was done in a 3d program without sculpting. anything with color that looks like detail was painted on. it has form without being sculpted.
this approach might be easier for you to get the base shape than sculpting I couldnt post an image. here is a link
here are two more that I did for others
you should try box modeling the body out. foot goes here, calf here, knee here, pelvis, etc. while it may not look like it. thats how the first link is made
patch box model