Claudie Haigneré tells about rituals surrounding a spaceflight. Here too, she tells about having to see a movie called "White sun of the desert" (it's got nothing to do with space, but Gagarin watched it, so all the following cosmonauts must see it too.
For Shepherd's flight
And Tito's experience with peing on the rear right tire of the bus (because Gagarin felt that last urgent need on the place).

In De Winne's book, he explains that the cosmonauts must go to Gagarin's office at Star City (near Moscow, just before leaving for Baikonur) tp visit it, sign a notebook. The crew goes to Moscow, puts flowers to Gagarin's and Korolev's tombs.
Once at Baikonur, every step is part of the ritual The capsule is visited in its assembly hall but they are forbidden to see it on its launchpad before launch day.
On launch day, they sign their name on their bedroom's door. They break a glass (for a toast) to the success of their flight. Toasting means drinking then praying.
During the bus trip to the cosmodrome, they see a video (a summary of their training).
After suiting up, they salute the president of the State Commission who tells them the launcher is ready. Then the bus ride to the launch pad (with the pee stuff).
On the launch pad, they climb stairs and on the last step, turn around and salute the crowd.
In space, there's the salt and bread gift exchange (well, maybe not anymore on ISS, but always with Mir).

Good luck to Lu and Malenchenko!

Raoul