I think it looks neater to put a line space before each comment (excluding the first).

i.e.
```Python
def make_plot(projection_name, plot_projection_crs, plot_region_limits):
    # Create a matplotlib Figure.
    fig = plt.figure()

    # Create a matplotlib Axes, specifying the required display projection.
    # NOTE: specifying 'projection' (a "cartopy.crs.Projection") makes the
    # result a "cartopy.mpl.geoaxes.GeoAxes", which supports plotting in
    # different coordinate systems.
    ax = plt.axes(projection=plot_projection_crs)

    # Set the displayed region (display coordinate values).
    ax.set_xlim(plot_region_limits[:2])
    ....
````