I often see suggestions to duplicate background layer and change the blending mode of the duplicate layer to achieve certain effect. For example it is often recommended to set the duplicate later to blending mode Soft Light and lower opacity to boost color saturation and contrast.
One problem associated with this method is the fact that every duplicate layer take space in the resulting file size. The other problem with this approach is that the steps performed on one image need to be re-applied to the other images in the batch.
There is a simple solution to those problems. Instead of duplicating the (background) layer, simply add one of the adjustment layers, such as Curves, Levels, Hue/Saturation and some others and set the newly added adjustment layer to the required blending mode and opacity. The result will be exactly the same. This technique does not add almost anything to the resulting file size. The adjustment layer can simply be dragged to the another image, effectivly copying the settings.
The advantage of using adjustment layers is even more apparent when the background layer must be diplicated several times and set to diffrent (or the same) blending modes and opacity.
