Keyboard shortcuts are fantastic tools to speed up processes and work at speed in Photoshop. You may find that some processes that you regularly use do not have a keyboard shortcut associated with them. One simple process that I use several times a day is to use the ‘flatten image’ option within the layers menu. There isn’t a shortcut programmed for this in Photoshop. But if you follow the process below you can set a keyboard shortcut to flatten images or use this method to setup or modify a keyboard shortcut for any other Photoshop menu option.
First of all open the keyboard shortcut menu. In the main menu you can find this under edit. Edit > Keyboard Shortcuts. You can also use a photoshop shortcut to open this panel which is Alt-Shift-Ctrl-K (Option-Shift-Apple-K on a mac).
With the panel open you will see a list of categories, these are actually the same as the Photoshop main menu options and you will find the sub categories within each option by clicking on the arrow to the left of the name.
The Flatten image option is within the layers category, the list within layers is also the same order as the main menu options, so Flatten image is nearly at the bottom of the layers list.
When you find the option you want to change, click on it to highlight it.
Press the key or combination of keys that you want to use as the shortcut. I first tried to use the F5 key. Upon trying this as a shortcut I found that it was already in use. You will get a warning in the bottom of the panel to let you know what is using it. You can choose to use the shortcut but it will stop the existing keyboard shortcut in most cases. (If you have a keyboard shortcut setup with an action this will normally continue to override what you choose here, so if the warning mentions an action item you will need to delete the action in order to use the shortcut with one of these menu items). I always think it is best to continue trying different key combinations until you find one that isn’t in use so you aren’t potentially ruining other processes.
The second combination I tried was Shift-Ctrl-R. There was no warning message in the bottom of the screen, so this keyboard shortcut is free. Once you click ok, this keyboard shortcut is in use and you can use the combination of keys to use the keyboard shortcuts from then onwards.
I have used a PC to show how to set up keyboard shortcuts – this process is exactly the same on a mac, you will just need to use the Apple key instead of the ctrl key on a mac.