Smart objects are wonderful and very useful. They’re famous for their nondestructive properties, especially for using filters on them, which become smart filters. With smart filters, you can change anything after the fact. There’s another thing for which smart objects are brilliant that doesn’t seem to be shouted from the rooftops as much, and that’s the ability to nest layers. You can select multiple layers in the Layers panel, Right-click on any selected layer, and choose Convert to Smart Object. All the selected layers will be nested into a single smart object. This reduces the clutter in your Layers panel since the smart object is a single layer. You can apply filters, layer styles, masks; you name it. When you double-click the smart object’s thumbnail in the Layers panel, it opens in a new window with all the layers intact. You can change anything in this new window. Save and close this document, and the changes update back in the main document. This is often a much better option than Stamp Visible. 

This tip previously published in Colin Smith’s Photoshop Tips column, in the May, 2020 issue of Photoshop User magazine.