For drawing tiles using image instances in Photoshop like the ones in the last video:
- Left Click on the tile layer
- Convert to Smart Object
- Copy the Smart Object Layer 9 times on a 3x3 grid
- Left Click on one of the Smart Object Layers and select Edit Contents
- Separate the 3x3 grid window and the one with the Smart Object Content, edit the last one and changes are reflected on all the instances.