Update a Basic, Beige, Builder's Bathroom with 5 Simple Steps (and less than $100!)

We all have seen / had / know someone who has a bathroom like the one in my rental. It's functional, spacious, there is nothing really wrong with it, but it is just a bit boring! There is nothing defining it.The trouble with rentals, of course, is that you cannot do much about the major fixtures and finishes, but it's amazing what a little decor can do to give a space like this some glamour! I