1. Arrange the layers in the Layers panel so that the base layer with the mask is below the layers that you want to mask. 2. In the Layers panel, hold down Option. Place the pointer over the line between the base layer and the first layer above it that you want to include in the clipping mask (the pointer changes to two overlapping circles and click. [More Info](https://helpx.adobe.com/photoshop/using/revealing-layers-clipping-masks.html)