When you aren't sure which tween room style might fit your daughter the best, take a cue from her wardrobe. Does she favor looser-fitting, flowing clothing à la Mary Kate and Ashley Olsen? Do her outfits channel a bit of '70s hippie? If so, boho chic could fit the bill.
Think patterned tapestries for the walls and perhaps a gauzy canopy for the bed to add a slightly Moroccan feel. Floor-length curtains work well for a softening touch. You could also integrate beaded curtains across closets or storage spaces. The color palette should pull from richer earth tones, such as burgundy, chocolate and plum.