Brainstorming

My first theme is "The Sea". How to start? To get my ideas sorted I draw some quick ATCs:
You can look at the sea from different points:
1. you can look at the whole. That means
- the sky above the water with sea birds,
- the surface of the water with ships, boats, lighthouses, swimmer,
- the animals under water like fishes and jellyfishes,
- the live on the bottom of the sea with mussels, snails, crabs.
2. you can look only at the surface. That means at the structure of the waves or the colors of the water.
3. you can concentrate on the fishes.
4. you can only look at the bottom of the sea.

I am not yet sure which possibility I will choose.