I think the only guideline is to share what you think is worth sharing. In my opinion lxde is the best compromise between performance, ease of use and easy configurability. Afaik fluxbox heavily relies on using the right mouse button which is sort of a pain in Easy Debian. And it has quite tiny desktop elements by default which might be hard to decipher on the N900 if you're over 40. But I'd be happy to be proven wrong and see some well-done fluxbox implementation in ED.