If your bathroom needs an upgrade, there are a few things you can do to make it look more high end.
Clean & Put it Up - First you need to get rid of clutter and the cheap looking accessories you have holding your soap and other toiletry items. A clean and sparkling bathroom with some nice aromatherapy and opting for a beautiful soap dispenser or toothbrush holder will immediately give the room a more upscale feel.
Rich it Up - Add some other rich metals for your fixtures if your budget allows (like replace a chrome faucet with some gold toned or brass fixtures) and if it doesn't, add some rich metal accessories to the room. A hardware upgrade for the vanity might be in order!
Sit it Up - Luxury bathrooms usually have some sort of seating in it. If a full size chair won't do, add a beautiful rustic stool.
Rug it Up - Get rid of that old bath mat and add a nice Persian or Turkish rug to the space. They fade nicely and will be soft on your bare feet.
Light & Style it Up - Good lighting is important in a bathroom, but that doesn't mean it has to be ugly! Add some luxury lighting fixtures if you can and upgrade that old medicine cabinet with a beautiful picture framed mirror. It will immediately make the room feel custom and warm at the same time.