The documentation suggests that we can use Roll20 to create our map from tiles.
This works, except that it is rather painful to repeat an arrangement of tiles - I have not seen support for copy-pasting of multiple tiles. When you uses Shift+Click of multiple (e.g. 4x4) tiles, CTRL+C, CTRL+V scatters the tiles into a few heaps. While this behavior is understandable, and may not need to be changed, support for handling groups of tiles would be appreciated.
For example, we could have the option to select multiple tiles and group them, so that they can be copy-pasted as a unit. Alternatively, something like ALT+DRAG for creating a copy in a specific place would be a fast way to conveniently fill the map with tiles.