SET: idioms [advanced]

Phrase enter
Last year, a group of activist cartographers started walking around the Nairobi city slum Mathare typing landmarks into hand-held GPS devices. The idea is to make slums a reality for people who would never set foot in one.
Phrase begin something
Amtrak has set in motion its plan to offer writers a rolling residency aboard their trains. The trains promise the romance. The writers will have to do the rest.
Phrase firmly established and very difficult to change
set in stone
Scientists once thought that after childhood, much of the brain became set in stone. Findings in the past few decades have proved that it remains more moldable than previously thought, even as we age.
Phrase cause to ignite and burn
set on fire
The Burning Man festival came to its traditional spectacular conclusion when the huge wooden effigy that gives the event its name was set on fire.
Phrase hope strongly to achieve or reach
set its sights on
Apple has set its sights on replacing the wallet with a new mobile payments platform called Apple Pay.
Phrase get started
Ship designers set sail, turning back to wind to help propel boats across the sea. The new vessels, mainly still on drawing boards, look nothing like the graceful schooners and galleons of the past.
Phrase prepare the way for something to happen
Tradition demands that statues depicting Ganesh are praised through prayer and offerings and then released into the sea. This will take away the year's misfortunes and set the stage for a prosperous future.