If you upload a drawing (scaled) that lists all measurement in inches, you will be able to receive advice/suggestions on what would look best for your space. Also, include some photos of the space!

How much room do you have?

I used this sconce in a guest bathroom. Only 3" wide.

I don't like sconces so for me a nice retangular light with good lighting above the mirror would be my choice

Pendants will bring the lights down to eye level, which will allow you to avoid shadows.

Once side like this? This powder room is barely 36” wide

What is the width of the vanity and medicine cabinet; how deep is the medicine cabinet; and what is the distance between the top of the medicine cabinet and the ceiling?

Pendant lights on either side.

BeverlyFLADeziner: "You can run the electric through the face of the mirror!!"

She has a medicine cabinet there.

Place the medicine cabinet on the side wall.

Thank you to everyone who replied. I think we're going to go with a good overhead and possibly a niche on the right with a light of some kind. I'm sorry I could not upload a picture. Demolition is in progress, so a photo would not have helped. The width of the medicine cabinet is 36", and the cutout has already been made, so no wiggle room there. (We thought we'd have more space, but we are in an 80-year-old building in NYC and you never know what you're going to find inside the walls. In this case various pipes could not be removed; they are the problem.) I appreciate all of your suggestions and will consider a few of them. Many thanks!

"I think we're going to go with a good overhead"

A common recommendation is to choose a vanity light that's 75% of the width of the vanity.

To avoid any shadows from the medicine cabinet, choose a light that protrudes beyond the front of the cabinet and don't mount it too close to the cabinet top. For example, the Visual Comfort Span that I used is 5-1/2" deep. I'd use a dimmable 3000K LED light with a Lutron LED+ dimmer.

Great tip to use a deep enough fixture, mounted sufficiently high to allow for more light. Many thanks, WDC. You have great ideas!

I'm not much into dark-colored decor, but I love that black-with-white-flowers wallpaper.

It is quite dramatic, isn't it!