All non-mourners stand in two rows on the way back from the grave.  The mourners walk between the rows and are greeted with this phrase:
 Ha'makom yinachem etchem b'toch she'ar aveilei tzion v'yerushalayim.
Then, the mourners remove any shoes which contain leather from their feet before walking between the rows of people. (Take other non-leather shoes to the cemetery so they can switch into them after the burial).
 

A mourner enters the synagogue on Friday evening before Mizmor shir l'yom haShabbat (after the main part of Kabbalat Shabbat has finished).
Reason Mizmor shir is the actual starting point of Shabbat.
The congregation stands and, as the mourners walk in, greets the mourners with “HaMakom yenacheim etchem b'toch she'ar aveilei tzion v'yrushalayim.