I think it would be a great idea to include single space decorations that would fill in unwanted, empty spaces.
For example: There could be a decoration with leaves that have fallen onto the ground along with some acorns, or a sandy spot with a small palm tree and a crab. There could be baby parks which could include a small space with tiny bushes shrubs and trees or maybe a baby park with some cobblestones and a bench. Some small animals like squirrels and bunnies running around would also be really cool! These are just some examples but the list could go on and on.
Another idea is to have more landscape types instead of just the 5 (water, grass, sand, dirt, and ice)
Multiple shades of grass anywhere from bright green to brown would be a great feature. This would look really neat and would make it so you could correspond your town with the seasons. Also, for spring time, there could be an option for grass that would have small wild flowers mixed in. For winter time you guys already do a frosty grass which is really cool! Again there are probably plenty of other ideas for landscape types that would look great. These are just a few of my ideas.
Many times when decorating my town, the empty spaces do not look appealing to me. It would be great to add these features to the game!