Common themes I noticed in submissions:

1. Flowery, swirly pretty stuff
2. Symbol of a political/ecological/philosophical suggestion (required explaination)
3. Ultra-cutesy cartoon animals/vegetables/people
4. Trees/roots (stuff that grows)
5. BIRDS. Lots of birds.

I'm desperately trying to write a popular slogan but am having trouble getting one that more than 30% of people like. Its hard!

Anyway, I'm drawing an actual design that you should watch out for.