Make a scale drawing of your wall set up on graph paper. That way you get to see if the lights overpower the size of the mirror or not. Select something you like to look at. More light is better, IMHO. It is always possible to downsize the wattage and bulb types, but you cannot upsize in any given fixture. In my pre-remodeled bathroom I had 12 globe lights over a 7' vanity. In my post-remodeled bathroom I have 5 on top and sconces on either side, plus recessed ceiling lights. Choosing the type of light bulbs is a whole nother deal. Good luck. What you don't want is shadows, whether you are shaving or applying makeup. -Babka

I think a 3-light will probably work. A 2-light in a powder room, maybe, but you'll want something like 3x65W equivalents of light to get ready in the morning. As long as it's not wider than your vanity, a little larger or smaller than the mirror is not likely to be noticeable.

Hi Elaine, 120 watts of incandescent light should be more than adequate at the mirror. Yes, you should consider LED bulbs. To my eyes the best currently available are coming from Philips & CREE. Be sure to choose a dimmable bulb so you can vary the light level.

IKEA https://www.ikea.com/us/en/p/arstid-led-picture-light-nickel-plated-10355627/ https://www.ikea.com/us/en/p/brynet-led-picture-light-black-90389223/ https://www.ikea.com/us/en/p/brynet-led-picture-light-silver-color-70389224/ https://www.ikea.com/us/en/p/maglehult-led-cabinet-picture-light-black-30464890/ You can also use swing arm library lights to illuminate the art.