This is the way I used to do it, although I didn't make enough free sites to tell you if it's a good way:
www.xx.com/amateur/index.html
http://www.xx.com/amateur/main.html,....gallery2.html (renamed using keywords)
www.xx.com/amateur/images/ (pics,thumbs & graphics go here)
for LL's that accepts mirrors:
www.xx.com/amateur/index.htm
www.xx.com/amateur/warning.htm (optional)
www.xx.com/amateur/sexy-warning.htm... (very optional)
Then I go one directory down for more mirrors:
www.xx.com/amateur/cutie/index.html, main.html, gallery1....
www.xx.com/amateur/sexy/index.html
The only problem for me personally with this is most of those pages would get dup penalty, so for sites I submitted to lower traffic LLs, it was also likely it wouldn't get any SE traffic either. So if I decided to build free sites again, I wouldn't bother with too many mirrors.
If I had the option of linking all the mirror index pages to a single main.html page instead of linking to different main.html pages, then I'd have unique SE listings for all the pages. Unfortunately, alot of LL's don't allow that, probably for good reason.