My bathroom has a single globe light fixture above the mirror that makes everyone look slightly ill. I've complained about it exactly once to my landlord, who looked at me like I'd asked him to install a pool.
So I found my own solutions. Three of them, all reversible, all under $150 total.
Upgrade 1: Better Bulbs
This sounds too simple but it's not. Swapping the existing bulb to a 2700K warm white LED cut out about 60% of the harshness. Takes 30 seconds. Free if you have the bulb. Do this first.
Upgrade 2: Plug-In Vanity Sconces
Plug-in bathroom sconces are real fixtures with a cord that runs to an outlet. Mount them with adhesive or very small removable anchors, run the cord behind the mirror, and you have side lighting that rivals any renovation. The mirror hides the cord beautifully.
Upgrade 3: A Portable Task Light
A small, rechargeable pendant light on the back of the toilet tank or on an open shelf adds warmth without any installation. Charge it like a phone. Move it when you need to. It sounds janky but looks genuinely good.
Shop this post: bathroom sconces and bathroom pendant lighting