It’s easy to add facial hair to a male model photo, with the right Photoshop tools.
Simply create a new layer and select a small hard-edged black brush (1px-width should do it). Open a new document, around 150 x 150px and apply a few random squiggly lines. Once happy with this line pattern, activate the Define Brush Preset dialog box, by pressing Cmd/Ctrl+A and going to Edit>Define Brush Preset. Name your new brush before saving in your brush styles.
Now we need to create a realistic pattern for this effect to seem authentic. So, activate the Brush Presets palette and enable Shape Dynamics from the Brush Tip Shape options. Activate Size Jitter>Control>Pen Pressure and adjust the Angle Jitter until you’re satisfied. Set its Control to Off. Also edit your Color Dynamics Hue, Saturation and Brightness Jitters, and Other Dynamics>Opacity Jitter for optimum effects. Now you can go ahead and apply your brush to create your facial hair.
Of course, editing tone, blending modes and size will contribute to the effects, but you should quickly discover what works best where and for your particular model with a little experimentation.