Comment on portfolio by SakoraDemon

They're right. The answer is hard work and practice. Draw by looking at someone and drawing them. Get feedback by posting thumbnails in the Deviation Thumbshares section if you want it. Do a ton of work and then select the best one(s). You may be able to find free or inexpensive life drawing groups near you by doing an internet search. Otherwise here are some reference and figure drawing websites:
human anatomy for artists: [link] small images are free/ large images available with membership
human comic art reference photos: [link] huge professional photo reference site
lovecastle: [link] male, female, big cats, horses, hands, heads
pixelovely: [link] people and animals
PoseManiacs: [link] anatomical drawing references
Quickposes: [link] nude photos for figure drawing
Zvork Virtual Lighting: [link] interactive lighting on 3d human models

Also consult the website for the art school if you need any specific info about their portfolio requirements.