Canon Funerary Practices of the GFFA
Jedi Funerals
From Wookieepedia: "Members of the Jedi Order had humble funerals which were held in the Jedi Temple, as they did not fear death or value worldly possessions. Jedi attendees wore their usual daily attire, while non-Jedi guests, including honorable ones, wore modest clothing out of respect. The deceased's body would be placed in a casket which was then lowered and sealed in a slot underneath the floor. A bright light would then emanate from a circular opening in the seal, signifying the dead's ascendance."
This is from the "canon" tab of the wiki page, and seems to be mostly based on that batshit face-off arc from TCW. One of the most well-kown Jedi funerals we get to witness is Qui-gon's, which took place on Naboo and followed the Naboo custom of cremation. But, it seems that the Jedi tended to practice entombment when possible on Coruscant, unless this chamber in the floor is the entrance to a cremation retort. This is somewhat likeley, consideringing the room they are in isn't lined with graves. It looks like a space meant to be reused. Of course, they don't elaborate on what happends after a body is lowered into the ground. It's possible that then, caskets are stacked in sort of a mass grave, which would be very Jedi, honestly. In our world, there is quite a history of more community-minded cultures utilizing communal graves. But again, it's also possible that a cremation takes place after this and then ashes aere placed somewhere within the temple or scattered.
Ferrix Funerals
From Wookieepedia: In Ferrix, upstanding citizens as well as members of the Daughters of Ferrix would receive a public funeral which was held in the streets of the city. Before the ceremony, their body would be cremated, its ashes mixed with mortar and Ferrix dust and pressed into a funerary stone which was then inscribed with their name as well as date of birth and death in Bazeese script. In the day of the ceremony, the stone would be received by a person close to the deceased, usually a family member or close friend if one wasn't available. This trustee would then along with Daughters of Ferrix, Honor Guards and the Honor Guard band lead a parade of Ferrix citizens from the deceased's home to Rix Road all the way to Fountain Square where their holorecorded "Truth" would be broadcast for the crowd. Movements such as "Forming Up", "Unto Stone We Are" and "To The Sky" would be played by the band during the parade, while passers by would stop and stand to pay their respects. Upon reaching the Square, the procession would form around the holoprojector broadcasting the Truth while chanting "Stone and Sky"; silence then befell upon the crowd as the deceased's word "lifted" them. After the ceremony, the funerary stone was placed in a city wall, as the deceased metaphorically "gave their body to support those who remain".
This, to me, feels like the most realistic and familiar funeral we've seen in the GFFA. Honor guards, processions, etc. are all things I see on the daily as a mortician. Placing the stone in the wall is even familiar! Cremation has surpassed burial in popularity (for America, at least) and one of the most often chosen final places of rest is a niche in a wall. A little different than crafting a brick, but not terribly so. The biggest deviation I saw in Maarva's death from mainstream American culture was her shrouded body, as this is not so common. We tend to fear the form of a dead body. We most often see a body in something more substantial, like a casket. Even when funeral workers are removing a body from it's place of death, we put a cover over it, obscuring the shape for "modesty." And, members of the deceased's family are rarely the one's wrapping it up. The fact that Maarva's body was so lovingly tended to by her family and friends even before it was taken from her home shows a level of comfort with bodies that's sort of been erased from modern society. All of this put together leads me to see Ferrix funerals as deeply intimate, but also a big production. It's a lovely balance of DIY community death care and more "traditional" funerals with an order of service, etc.
Naboo Funerals
The naboo believed that a body body of a deceased must be cremated within two days time in order to return the deceased's spirit to the planet. A popular location for Naboo funerals was the Theed Funeral Temple, near the banks of the Solleu River. According to "Complete Locations," after the ashes were retrieved, they would be scattered into the Solleu from the bridge of the funeral temple. This was where we witnessed Qui-gon's funeral, and was the eventual destination of Padme's processions, I assume. There are many real world cultures that have similar time requirements for disposition, but most that I have encountered relate to burial. However, there is precident. We also very memorably see that that practice both open-casket viewings and pyre cremation.
Dathomir Funerals
We don't know much about the actual funeral rites of the Night Sisters, but we do know that they enshrine their dead in organic "pods" that the reanimated dead can emerge from to protect their sisters from outsiders.
Mandalorian Funerals
Mandalorian funeral were varied fom clan to clan, culture to culture. In combat, many Mandalorians were buried hastily where they fell, or cremated on a pyre. In combat against other mandalorians, fallen enemies were given the same respect as allies, because in the end they are all mandalorians.
Corellian Funerals
In Karen Traviss's book "Bloodlines," Corellians ashes were turned into gems.
Wookiee Funerals
In "Agents of Chaos 1: Hero's Trial" by James Luceno the characters attend Chewbacca's memorial service. A proper funeral was no able to be held, because his body was not recovered. It is noted that if a funeral had taken place, outsiders would not have been invited. The Wookiees closely guard their funerary practices, and outsiders do not even know what they are! There are rumors though, ranging from cremation, to lowering the body into the depths of the forest, to dismemberment for the purpose of sky burial. Personally I like the sky burial rumor the best, because it feels very Wookiee to me.