Append the filename of the document you want to print to these commands.
To set multiple options, specify -o multiple times: -o foo -o bar.

To print certain pages of a document
lpr -o page-ranges=5-10

To print double-sided
lpr -o sides=two-sided-long-edge

To specify paper size
lpr -o media=a4

To force landscape printing
lpr -o landscape
However, this sometimes cuts parts of the document off and makes it not fill the
whole page (but with the correct orientation). In these instances, it's probably
necessary to simply NOT specify -o landscape.