https://www.be-rad.com/2013/10/31/how-to-tile-an-image-in-photoshop/

This is a quick tutorial designed to teach you how to tile an image in photoshop. Before learning this easy method I would cut/paste a piece of my image until it filled the screen. That was such a waste of time. After you learn this trick it’ll literally take you 16 seconds to tile an image in the future.

You want to turn this:

into this:

The internet just exploded

Steps:

1. Open Photoshop
2. Select the area you want to tile (you can press ‘m’ for the select tool and click/drag to select an area)
3. From the menu select Edit->Define Pattern
4. Name your pattern and click OK
5. Select the Paint Bucket tool (press ‘g’)
6. Change the Source from Foreground to Pattern (see image below)
7. Choose your pattern from the drop-down menu (see image below)
8. Click in your image to paste your tiled pattern

Note: Make sure to create a new layer when you use the Paint Bucket Tool. This ensures you don’t mess up any of your current layers.

If you enjoyed this tutorial please check out the games I make in the sidebar