1. First of all you must open an image that you want to put frame on.
2. Select the 'Rectangular Marquee Tool (M)' and make a rectangular selection in the middle of the image. The space between selection's borders and the sides of the image will be your frame.
3. Now goto main menu and 'Select -> Inverse' or press 'Ctrl + Shift + I', the result will be two discontinuous rectangles as shown below.
4. Then select the 'Brush Tool (B)' and draw over the delimitated space by the rectangles. It doesn't matter if you draw outside this area.
Or you can simply choose menu 'Edit > Fill' to fill the area with any color. Next image shows the result.
5. Now go to main menu and 'Layer -> Layer via Copy' or press 'Ctrl + J', this action will get you a layer with the painted area of the previous step. Then, double clicks over the new layer to get into 'Blending Options' (or right click and choose 'Blending Options' from the menu). In the 'Blending Options' window give the frame the style that you prefer. I use the settings below:
6. Next image shows the result of this final step.
More Tutorials: 
