Install an 80-tooth carbide blade in your power saw. Most power saws come with a 40-tooth blade. You need 80-teeth or more to cut picture frame moulding. See the Framing4Yourself Power Miter Saw Package
How to Build Wood Picture Frames
Press the moulding against the back of the fence with the ornamented side up and the rabbet (in-cut) side of the frame facing toward you.
Slide the moulding down the fence extension to the point on the scale that denotes the size you want to reduce it to. More about measuring. When you make picture frames, measuring accurately is crucial. If you don’t have a fence extension with a 45-degree scale, consider the Logan Double Saw-Fence Extension.
Lower the spinning blade through the moulding to make a mitered (45° angle) cut. Repeat for each of the four frame sections until you have four frame sections miter cut at each end.
Test the pairs of frame sections for exact length by laying the frames on their backs and lining up the miters. If you detect a discrepancy, sand to correct the miters using a rotary sander. See the Logan Elite Precision Sander
Put a dot of wood glue on the miter face. Then clamp two mitered moulding sections into a corner clamp. Tighten the clamp. The joiner shown here is the Logan Studio Joiner but there are other joiners. To see an article comparing the different joiners, click here.
A V-Nail is a V-shaped staple with a sharpened edge. Place it on the nose of the frame joiner sharpened edge down.
The nose of the frame joiner is a magnetic pin protruding from a black cylinder. The V-Nail with cling to it.
Turn the clamp over so the moulding is ornamented side down. Slide the moulding under the magnetic nose of the joiner (red arrow). You are ready to make a picture frame.
Arrange the V-Nail so the wings are on either side of the seam and press down on the lever. The magnetic pin retracts into the cylinder and the V-Nail is squeezed firmly into the wood at the back of the frame.
The V-Nail sinks into the wood until it is flush. Each V-Nail is designed to deflect against the grain of the wood so the seam is pulled tight as it sinks. Most framers also use wood glue for added strength.