One of the mistakes people make is to assume the needs of younger children are the same as those of pre-schoolers.
I find in the main children under the age of 3 are not ready for themed activities or any kind of structure beyond their individual routines.
I use individual planning with under 3s, looking at their interests, learning styles, schemas, things they are doing here and at home and other settings if appropriate.
I then use these observations, plus comments from the children to formulate their next steps.
During the day I plan a singing / dancing session and at least one reading session and the timing of both is flexible.
So for room layout, I focus on small boxes of toys and games which I know they enjoy, regularly changed to meet their changing interests... on shelves they can access.
Hth