Here are some ideas and tutorials for framing a bathroom mirror that is already in place.
Here are some framed mirror projects created by other Hometalk members. Wishing you the best.
There’s several ways, depending on your tastes:
here are some https://www.hometalk.com/search/all?filter=diy%20mirror%20frame
sometimes it is easier to find a frame and have the mirror cut to fit. Here are a couple of samples I did.
You might look into Mirror Mate!
you can do wood or tile. I’ve seen quite a few projects on the subject.
I just made a simple one out of cedar lumber for a mirror with clips. You can see how I did it here: https://www.flippingtheflip.com/2019/12/how-to-diy-frame-wall-mounted-mirror.html?m=1
Hi Roy: You can use some molding that has a lip on the back. The home improvement stores carry it in various widths and designs. Just cut it to the size you need. If you are going to do a miter cut, get more molding than you need and practice, practice, practice! :) Good luck
Quick way would be to stick the mirror to a backboard that is big enough to also fit a frame to it. You can mitre the corners or butt them - depends on your style.