One of my favorite rooms in the house.  This powder room is all about the red.  
And the wallpaper, of course.

Powder rooms are, in essence, smaller rooms.  SO – USE THIS TO YOUR ADVANTAGE!!!  You only have x number of square feet of wallpaper, tile, one window, one light fixture, etc.  Go all the way!  I love to turn powder rooms into a little jewel box.  Someone once told me, if you want to know the quality of a restaurant, check out its bathroom.  That has always stuck with me.  You have a captive audience in a powder room.  They are most likely a guest, and most certainly alone.  
So, the next time you fall in love with a fabric or stone or wallpaper, but it’s too steep for your budget – work it into the smallest room in your home with the most impact.  Oh, and put in a single, tall thin bud vase with a single stem of the freshest flower and light a candle.  Fantastic.