Adding a Command to an Action
Actions are very versatile; in fact almost anything that can be done to an image can be placed into an action. You might find that as you perform an action, you need to add an additional command. You can do this with ease, that's why actions are so great to work with. For example, you might create an action to convert an image from the RGB to the CMYK mode, and after you save the action; you decide it would be great to include a Curves adjustment. You don't have to throw away the old action and start all over, all you have to do is select where the command will be inserted, restart the action and perform the new step. The Actions palette is a powerful time-saving tool, and if you forget a step, it's also a breeze to modify.

Add a Command to an Action
Open a document, and then select the Actions palette.
Click the expand triangle of the action you want to add the command.
Click the command directly above where you want to insert the new command.
Click the Actions Options button, and then click Start Recording .
Add the additional command by selecting the filter, adjustment, or any other Photoshop option.
When you're finished adding commands, click the Stop button on the Actions palette.The next time the action is run, the additional command will be performed.