DIY Bathroom Mirror Frame

Measure the length and height of your mirror to determine how large of frame you need to create.

Select the trim you think best matches your bathroom or interior space. Consider combining multiple types of trim such as chair rail and wainscoting to get a layered look. Purchase moulding from The Home Depot where an associate can cut it for you for free.

Measure your mirror and materials again to ensure a proper fit. Select the wood you would like to use on the outer frame. Then measure the wood that you will want to be your outer piece. Mark the wood measurement on the outer edge of the wood. You want the corners of the moulding to meet at a 45 degree angle, so keep that in mind when you're marking it.

Cut a 45 degree angle cut using the mitre box and saw. Use the mark you made as the outer part of the cut then cut inward. Cut the 45 degree cut going the other direction at the other end. Continue measuring and cutting all four sides.

After cutting all the wood, use a high-grit sandpaper to soften the edges. Then use wood glue to attach the four pieces together.
Do NOT worry if they don't fit perfectly—you can use paintable caulk to achieve a professional and seamless look.

Consider using spray paint to achieve a high gloss finish, or consider interior paints such as specialty finishes in a metallic gold as an alternate way to add a luxe, gilded look to your frame.

Arrange the pieces to mount to your mirror. Glue the middle of the back of each strip of moulding. Install by putting your wood onto the mirror.

Fill any small gaps in the corners with caulk. Once that's dry, paint it to match.