GG hit on most topics that I was looking for however, I'm just gonna rattle off my list.
2-3 galleries of 10-15 pics each.
150x150 sized thumbnails (larger saves bandwidth and looks better)
Site NAMES and DESCRPTIONS that make sense
Categorized by CATEGORY and crosscategorized by the site its promoting
Personalized Ads that are related to the content promoting an appropriate site. (For example if its "Teen Marissa's Playhouse" and the content features Marissa, if the ads feature Marissa that's an extra added bonus)
Personalized pages that include the TITLE of the site in nice big bold obvious letters
No TEMPLATES! Sites that look the same as the last one is bad. Different colors, different ads, different layouts. Even if you guys think You've hit THE best template in the world, variety is important.
A large number of sites. 10 is not enough. 20 isnt either! Keep them coming.
Make more sites every week. Hire a guy who does nothing but build galleries and sites for you. Make sure he cranks out the sites. I hear MML does great FHS work
Do NOT, i repeat do NOT, think that a "free site" is a page that links to two of your free hosted galleries! This is a ripoff! Especialy when the two galleries contain different content! I dont know if other people agree with this but, its a pet peeve of mine. It just REEKS of laziness. Surfers want ONE set per site, of the same person. If they like the content, they want 20-30 pictures, not 10!
Lots of Text and Lots of Graphics. Variety again is important. Some ads should use exclusively text, others should use mostly graphics. Let one gallery sell on words, the other sell on nice graphics. This allows you to effect surfers that are effected by both
Alternative Uses for Traffic: Outback cash has the right idea!