Measure the mirror on the wall to determine the length and width of the frame (Image 1).
Using a table saw, cut the trim and molding pieces to size. Keep the table saw unplugged when not in use, especially when adjusting the blade or fence.
Now cut a pocket or slot in the primary trim pieces to accommodate the mirror edges (Image 2).
Note: Figure out your preferred finish for the frame first. It's easiest to apply the stain to the wood pieces before installation. Can be painted after installation.
Nail the sides of the frame to secure the trim pieces to the wall with the slots facing down over the mirror.
Continue nailing the top and bottom of the frame, being careful not to hit the mirror.
Add a table to the bottom edge of the frame (Image 1).
Cover visible screw holes with a thin piece, about 3/16" deep, to make a faux front, and fasten in place with small nails.
Next, add the final molds around the top and sides of the frame (Image 2).
Cover the nail holes with wood putty.
Add a silicone bead around the mirror for stability, wiping off any excess on the wall with a clean, damp cloth.
Paint or finish as desired.
