Layer Style

To change the layer style, for example texture/light, select "Layer Style" in the drop-down menu under "Layer" in the Top Bar menu. A number of options will be listed.

The "Blending" option allows you to change the opacity of the layer and create other blending effects.

Other options on this drop-down menu are:
"Drop Shadow"
"Inner Glow"
"Outer Glow"
"Gradient Overlay"

Each option has editing properties eg. size of pixels, range, opacity, spread - all which you can vary by using the scroll bar.