Doubleclick on the Double Exposure Kit by SparkleStock (Lite).atn file.
Doubleclick on the Double Exposure Gradient by SparkleStock (Lite).grd file to load the optional double exposure gradients.
In your Actions panel (Window > Actions), click on the Double Exposure Kit by SparkleStock (Lite) folder. Select the "Play All Effects" action then click on the play button on the bottom of your Actions panel.
After the action is done processing, all the effects will be prerendered as snapshots in your History panel (Window > History). Click on any of the snapshot to apply the effect.
You can enable the "Gradient Overlay" layer and use one of our premade gradients. To access these gradients, doubleclick on the thumbnail of the "Gradient Overlay" layer then open the gradient picker.
Photoshop Elements
Open Photoshop Elements then switch to Expert mode.
Open the Actions panel (Window > Actions). This panel can only be opened in Expert mode (not Quick or Guided mode).
Drag and drop the "Double Exposure Kit by SparkleStock (Lite)(Photoshop Elements).atn" file to the Actions panel.
Select the action you want to play then click on the play icon located on the top-right of the Actions panel.
Open the Layers panel (Window > Layers) to view the layer structure.
Notes
For best results, your foreground image should have a white background.
If you are getting error messages when playing the actions, ensure that your image is in 8 or 16-bit RGB mode by going to the Image > Mode menu.