The actual term Bohemian is the gypsy phrase for Good Home. The philosophy behind it is to live in harmony with the earth and all life forms. Therefore, bringing in elements of the earth, whether it is plants, ferns or crystals, into the space will assist.
At the end of the day, a true bohemian style is to have a room that reflects all aspects of yourself and your travels. What makes you comfortable and relaxed is the true basis of the style. As Oscar Wilde said "To love oneself is the beginning of a life long romance."