At first glance it may seem that pattern fill layers are sort of useless. However, when you explore a bit more you will see that they can produce wonderful effects.
1) Open up your picture. The one I am using is below.
2) Open up the pattern below in Photoshop Elements at go to Edit - Define Pattern. You can name it anything you want.
3) Go to Layer - New Fill Layer - Pattern. Select the pattern you made from the list.
4) Set the blend mode to "overlay".
5) Click on the brush tool (B) and select a large soft brush, I am using 100px. Make sure the color is set to black.
6) On the image below you can see the brush strokes I used on the layer mask thumbnail.
7) You can see the final outcome on my picture below.
Try to experiment with different patterns, blendmodes and brushes.
