custom fiberglass door panels

i was looking at a site telling me how to make fiberglass kick an boxs an shit but i was wondering would it be that simply to make my own door panels. I basically just wanted something flat real clean. I was goin to put some kind of fabric over it when im done cause i know if i jus paint it, it should look like shit. but it all seems simply enough an im would like to try it my self tomorrow. The site is http://web.njit.edu/~cas1383/proj/main/