Immediately after using most tools or applying filters and adjustments, you can “fade” the changes you applied by going to Edit > Fade, or pressing Ctrl Shift F (Mac: Command Shift F). In the Fade window, you can reduce the opacity of the last adjustment, as well as change the blending mode.
Keep in mind that the Fade command is only available immediately after you apply your changes. If you do anything else in between, including saving your image, you won’t be able to use it.
Also, the Fade command is not available on Smart Filters, but you can right-click on the name of the Smart Filter and choose “Edit Smart Filter Blending Options” and use this instead since the options are the same.