I really hope you adore this bathroom pick-me-up as much as I do. Janelle (whose blog is invite only) works at a fashion company, so the patterns used on the walls are very apropos.
What do you need to know about Mod Podging fabric pieces onto the wall? Treat it like several frames. Work small areas at a time and let dry before moving onto the next section. Also, if your bathroom is going to be exposed to moisture, you'll want to use a brush on sealer like Minwax Polycrylic. If you do that, it will last for years!