Save time with Photoshop Action scripts and Batch processing
Photoshop action scripts save you time on repetitive tasks, allowing you to get on with other elements of a job and improving work flow. The long and short of a Photoshop action is basically a recording of a process you go through that you can save and go back to later, for example I have 150 images that need resizing, changing to RGB and resaving, rather than spend time opening up each image changing the colour and resizing, I have recorded the process on one image, I can then drag an image into Photoshop click play on the action and it has quickly made the changes saved the image and closed.
If you want to really save yourself some time, create a batch process which allows you to choose a folder and allocate an action to the folder so that each image is opened the action made and then closed so you don’t have to drag the image into Photoshop, meaning you can have the process going on in the background while you get on with other work.
Action: Alt + F9
You can view a tutorial on Photoshop actions here
And Batch resize here