Create a Crop Preset with the Crop tool

Select the Crop tool from the toolbar. Note that the visible button shows the last tool used, so it may not show the Crop tool. Click and hold on the button, to see the other tools.

For more information see Crop Tool.

Select W x H x Resolution from the drop-down box on the Options bar. It's highlighted here in red and is the second item on the list.

Enter the dimensions in px (pixels), in (inches), or cm (centimeters). When entering numbers, Photoshop tends to remember the last type of measurement (px, in, cm), so to specify your measurement unit, add the abbreviation; px, in, or cm.

In the drop-down list on the Options bar, select New Crop Preset.

Do this after adding the dimensions, as in the previous step.

The screenshot shows the preset name, as suggested by Photoshop. If you're happy with that, just clikc OK.

Personally, I have a lot of presets and I prefer to use shorter names. The next step shows my preferred name for this preset.

I prefer preset names to be as short as possible, so there is less clutter in the drop-down list.

Here are some suggestions. If the preset is designed for printing, I include the resolution of (300), which means 300dpi (dots per inch), which is the default printing resolution. If the image is not being printed, but is for screen use, the resolution is not important.

Click on the drop-down list in the Options bar and select your preset.

If you have used another tool and select the Crop tool you will see a crop box around the image, without the crop overlay. In the following steps, the crop overlay is a Grid of Thirds, but other options are available.

If you select a preset the Crop Overlay will appear. If the correct preset is already selected, click on the image to add the Crop Overlay.

For more information about Crop Overlays, see Crop Overlay.

Click and drag the handles in the corners and along the edges of the Crop Box to resize it.

Click and drag on the image, inside the Crop Box, to move the image.

Press Enter (if you have a keyboard), or click the Tick on the Options bar.

IMPORTANT! Your image has now changed, so you will probably want to save it. But, be careful! Caution is advised.

If you firstly created duplicates of the original images, then it will be ok to just save the image, as you will still have the originals available.

If you did not create duplicate images, saving the image will overwrite the original image. This is not good practice, as you will lose access to the original image. You may have other ideas for it in future, which require the original uncropped image in its original size and resolution.

If you are working on original images, then instead of selecting, from the File menu (red highlight), Save (pink highlight), select Save As (green highlight), or Save a Copy (orange highlight). These are very similar and it doesn't matter which you choose. Both will preserve the original and save the new version as a separate image.

Save A Copy: saves the document under a new name, but the original stays open for editing, not the new one.
Save As: saves the document under a new name, and the new file stays open for editing.

You can easily delete any presets you no longer need.

Firstly, select the preset.

In the drop-down list on the Options bar, select the bottom item; Delete Crop Preset.