my tip for you is to save often, like every 10 seconds once you've perfected your next move, and reload of you dont do what you want to do. I've done all "least Portals" and a few least steps and time" ones i kinda had help using this website:
Portal Walkthroughs - Video Guides to Completing All Portal Levels
i know it's bad of me, but i got fed up!!
using only 10 steps on the first advanced map is pissing me off, my fewest is 13 steps, can't seem to cut it down...
it'd be easier with a PC but thats life!!