Is there any logical way to decorate the island?

Placement doesn't really matter to the game. It's up to you. Some like to decorate and make everything make sense; others just cluster them together so there are no hidden empty spaces. Just be aware that too many low-flower decoration and you will run out of precious island space.

The only thing I can add is placing your coin generating buildings near the front in an organized way. As you play collecting those coins really adds up and having to scroll around is a minor hassle. This is only for your convenience though and adds no benefit other then easy of collecting coins. Also if possible keep a small area clear for gifted bushes near there. Otherwise people will gift bushes wherever there is a spot and you will have to search for them.