It's their peaceful oasis. To make this happen once the door is closed, the room needs to have a serene atmosphere. If not use silk greenery to recreate the soothing feeling of nature. I do hope you manage to do these things. I have no clue how interior designers charge.
Designers work in a variety of ways.
For a personalized service, call interior designer Terry Ellis, owner of Room Service at the Michigan Design Center in Troy. She has package plans that include consultation and a tour of the Design Center. Questions of general interest will be answered.