There are two ways to create a Tile Asset in Unity; the first method is to directly create a Tile Asset from the Assets menu. The second method is to automatically generate Tile Assets from a selection of Sprites.
Import the individual Tiles or Tileset images for your Tilemap into your Unity Project by placing the Textures into the Assets folder. Select the imported images to view their Texture Importer settings in the Inspector window.
When importing Sprites for use in a Tilemap, use the following recommended settings. For further information about each setting, refer to the documentation on Texture Type: Sprite (2D and UI).
Create a Tile directly from the Assets menu by going to Assets > Create > Tile. You will be prompted to name and save the new blank Tile Asset to your chosen location. Refer to the documentation on Tile Assets for more information about the Asset properties.
Tiles can be automatically generated by bringing the individual Sprites or Sprite sheets of the Tiles directly into the Tile Palette window (if the window is not open, go to Window > 2D > Tile Palette).
First prepare and import the Tile Sprites, then open the ‘New Palette’ drop-down menu in the Tile Palette window. Select an existing Tile Palette from the list, or select ‘Create New Palette’ to open the Create New Palette dialog box.
After selecting the properties of the Tile Palette (refer to the Tile Palettes documentation for more information about the different options), select Create to open the new Palette in the window.
After creating or loading a Palette, drag and drop Textures or Sprites from the Assets folder directly onto the Tile Palette window. You will be prompted for the save location for the new Tile Assets. Select the save location, and the new Tile Assets are generated in the selected folder. The generated Tiles are also automatically placed onto the Palette.