How can I make over a bathroom vanity?

Sorry but I don't understand your question. Do you want to give the current vanity a face lift as in a new finish? If that is the case a fresh coat of paint on the cabinet and the same but different product to give the counter a look of marble or granite.

https://www.remodelaholic.com/diy-faux-marble-countertops/

https://countrylivinginacariboovalley.com/how-to-paint-a-countertop-to-look-like-granite/

https://www.homedepot.com/p/Giani-Granite-Sicilian-Sand-Countertop-Paint-Kit-FG-GI-Sicilain/203644684

Or this is what I did a few weeks ago:

https://www.hometalk.com/diy/bathroom/cabinets/my-little-bathroom-makeover-for-50-26272337

Hello there,

You could always repaint in another colour, or two colours (one to pickout the features), maybe!

If the cabinet is a standard size, you can buy a new sink/countertop combo in many textures/finishes like granite, marble, or soapstone at any home improvement store. You can paint the cabinet a new color or stain it to match the new countertop. And change the hardware/drawer pulls for a totally new look.

You could paint it and change out the hardware for a quick easy fix.

I would paint it and update the hardware. IF you like the hardware, refresh by painting with RustOleum hammered spray paint.

Thank you