The main aim of Photoshop actions is to prevent monotonous work and improve your work efficiency greatly. Actions are a series of tasks that you play back on a single file or a batch of files menu commands, palette options, tool actions, and so on.
Here is a set of 10 Photoshop Actions which will be useful for enhancing landscape photos, or creating abstract nature images. These actions are free to download so you can try them all and see which actions will fit for your images.