The staircase is a slightly picky detail, and it may take a while for players to figure it out. 

However, they can be simply broken down. 

Create a foundation (a level at the top of the sand base, or a level above it), and place two buildings at the edge of the foundation. 

Leaving space between them creates a set of stairs while leaving two spaces creates two stairs facing each other. 

Notice that the remaining three or more spaces do not produce stairs because the gap is too large. 

Larger staircases can be built, but they need a square behind them and buildings at least two blocks high.