Help Please (Any Advice would be great)

I know this might sound weird but I´d like to learn to build foam mockups.
Could you give me any advice? Any Online tutorials? Havent done it before and Im sorta desperate, cos I need to build some scooter parts 1:1.
Thanks, Cant wait for your replies.

…i just lay up a block of pink foam and carve/file/sand away what ever doesn’t look like what i want…coat it with rave gold (a high quality light weight bondo)…sand it…prime it…wet sand it…paint it…tada!

the following link was posted previously on this same subject; http://www.conceptart.org/forums/showthread.php?p=515788#post515788

thanks man