Amera Plastic Moulding has some new rolling dunes in 15mm scale available on their website to help liven up the look of your table.
From the update:
Amera launches a new set of 4 sand dunes suitable for a range of smaller scales including 15mm and 1:72. Details on the the website. Have a look at examples of their 15mm and 28mm ranges painted on their Facebook page too for inspiration