Well, you can have forums such as Gaming, Sports & Recreation, Media, Philosophy & Debate, Humor, Internet, Automotives, Entertainment, Graphics, Promotion/Webmastering, Literature, etc.
You can have like a Gaming Category for all the gaming related forums, a Lifestyle Category for all the Lifestyle related forums such as Automotive, Sports, etc.
1. Reception
1.1 Announcements & News
1.2 Feedback & Suggestions
---- Archive
1.3 Member Introductions
---- Question A Member
1.4 General Discussion/Off-Topic
---- Forum Games & Fun
---- Humour Me Corner
1.5 Debates
2. New Age Media.
2.1 Technology Bytes
2.2 Gamers World
---- Gaming Reviews & Feedback
---- Gaming Development
2.3 Beat Me Up(music)
---- Videos
2.4 Movie/TV/Onscreen Plaza
---- Movie Reviews
---- Downloads
2.5 Social Media
3. Creativity River
3.1 Portfolios
3.2 Request A Graphic
3.3 Graphic Discussion
3.4 Resources
---- Tutorials/Articles
3.5 Graphic Database
5. Other Discussion
5.1 World Events & Happenings
5.2 Sports
---- Football/Soccer
---- Rugby
---- Water Sports
---- On the Field
Anything like that? You could always add the last category to the first to have four main categories, and any forums that become inactive - delete after a week. Also you may want to have 100 pre-posts each section.