One way we made the original vanity in our master bathroom look more finished and elegant was by simply adding some knobs to the doors. It previously was completely naked when it came to hardware. I picked up these knobs at Home Depot for $1.79 each.
Since my doors didn't have any previous knobs, I had to drill holes for the knobs to be screwed on. You can purchase little plastic guides to use to make sure all your holes for the knobs are in the right place. I'm cheap so I just made my own guide using a scrap of carboard that had a corner. I measured on the door where I wanted my knob to be and then marked that point on the cardboard by lining up the corner of the cardboard when the corner of the door panel. I poked a hole through the cardboard where that mark was.
I then used a pencil poked through the hole to mark on each door where I wanted to drill the hole for the knob.
Then it was as simple as drilling the hole and screwing in the knob. Simple change, big impact. (And yes that is a cat in the window if you look at the reflection. She loves being in photos)