Each level has a tilemap as the base layer. Tilemaps are easy to build using the built-in editor. I wanted to experiment with the scale of the tiles. The actual pixel size of tiles is now 512×512 but I can scale it up or down to make the result look nice.
To get a better idea about how much they take up on screen, I decided to make another tileset, with a blueprint-style grid on it. In Photoshop I drew a tile with thin lines around the border and across the center. Also added a label with the tile number.
I didn’t want to export each tile manually, so I used the “data sets” feature in Photoshop where you can feed it a text file with values and it applies them to the assigned layers. Then do an batch export for each row of the data set and voilā: