Blend Mode in Smart Filters
In the olden days, you could control how a specific effect reacted to an image by choosing Edit>Fade (effect name). This would give you a blend mode option for the effect, as well as an Opacity control. The problem with this was you had no way to go back and modify that setting once it was completed. In Smart Filters, you have the option to set the blend mode and opacity of that effect, and still keep the control you need to modify it later. Just double-click on the Edit Blending Options icon that appears to the right of the Smart Filter in the Layers panel.