Measure the canvas dimensions
Cut four frame pieces to size
Miter the corners at 45 degrees
Sand the cut edges
Dry-fit the frame pieces
Apply wood glue to the joints
Clamp the frame together
Reinforce the corners with nails, screws, or corner brackets
Check that the frame is square
Let the glue dry completely
Sand the assembled frame smooth
Apply paint, stain, or finish if desired
Attach stretcher bars or backing support if needed
Mount the canvas onto the frame
Secure the canvas with staples, tacks, or clips
Trim any excess material
Add hanging hardware if needed