Anthologies: Theme Picking and Mini-Samples!

I am required to pick a theme for an anthology but I am very confused. I cannot seem to make up my mind about any sort of theme, and by the end of the day I'm left with nothing but many poems and a headache. It is really hard to pick a theme when you want to pick everything.

So I would really appreciate if someone truly helps me find a theme I can start with, and may know of poems that share a "similar" concept!

I have thought of children poetry as a theme, particuarly poems with the "sun"..
I have thought of swans.. the dark image of swans, or the beauty and marvel..

But right now, all I got is a headache and no answer!!

So if you could help me brainstorm for a theme I will be thankful!

Cheers,
M