How elaborate do you want to get here? There's the 2 links provided by Scipio here, but you could simply be descriptive as well. Also, it depends on who is conducting the service. Here are some examples:
1. The Pyre of the Dawnflower: an officiant of Sarenrae calls forth sacred flame, issuing blessings and prayers over the prepared corpse, which has been wrapped in white linen. The body is laid upon a bower of interwoven wood which has been drenched in kerosene which has also been blessed as per Holy Water. Finally, the officiant ends the ceremony by setting the pyre ablaze while they lead a dance in a circle at a safe distance from the fire while dawn rises in the east.
2. Unto the Wind and Waves: from a sea cave while the tide is going out, the body is preserved in a seaweed wrap and strapped to a thin pallet. A number of prayers and songs are delivered simply while mourners watch from a distance. Each is given a chance to speak their piece over the fallen, then when all who wish have participated the corpse is set afloat into the endless sea. A variation of this can be done from the rail of a ship, casting the body into the brine without any sort of a float.
3. The Honorifics of the Fallen Hero: the chosen of Iomedae are embalmed or preserved by magic, then given blessings to ensure the corpse will never be defiled by necromancy. After this, the body is ensconced in either specially prepared ceremonial armor or whatever vestments they commonly did battle in. Finally, a longsword is placed in the hands of the corpse before it is interred in the earth. During the whole process prayers are offered in ritualized stanzas. At the grave site, while the body is being laid to rest, the officiant delivers a scripted service which includes the Inheritor's Creed, a final blessing upon the soul of the fallen, and a retelling of Iomedae's sacred ascension. Finally, while the coffin is physically lowered into the earth and covered with earth, the officiant delivers a eulogy which accounts every deed in battle the fallen had accomplished. This eulogy requires at least one witness, usually the fallen's second or squire, though this can be a close friend or relative as well.
4. The Spiraling Dirge: The Lady of Souls requires a ritualized bathing of the body in sacred water, usually infused with the oil and perhaps the petals or blooms of black roses. During this baptism into the afterlife, hymns and dirges are sung. After this the body is cloaked in gray cloth while a number of ritualized spells and prayers are delivered to ensure preservation of the corpse, the peaceful transition of the soul to the Boneyard and the rejection of undeath in all it's forms. Once all of this is completed, mourners are encouraged to eulogize their loved one. Finally, the service is completed by the officiant, their assistants and the mourners assembled walking a spiraling pattern to where the body will be interred. This spiral could be as simple as a circle around a grave dug in the wilderness to as elaborate as a mile long, meandering funeral procession through a settlement to the mausoleum of a royal family.
That's just a few examples, based on different faiths of Golarion deities. Even though there are many gods that govern the Death domain, it is reasonable to presume that every organized religion has their own funerary rites and customs.
This should be further tailored to the environment of the practitioners. Desert-dwelling folk who serve Sarenrae for example may not have the material to build a massive pyre, so instead the corpse is interred in some kind of cave, while Gozreh worshippers of highland moors may instead sink their dead into a bog that is considered blessed or sacred in some way.
Death is personal, and the passing of a PC, if it is given the attention and honor of being described in the narrative of the game, should reflect the person they were in life.
I had a paladin PC that championed intelligent foes throughout the campaign. He always began every encounter using the Diplomacy skill and spent the majority of the game reforming a kobold from LE to LN, helping her become a functioning member of society and fighting to ensure her rights in the city at the center of the campaign.
He also came to an accord with several different fey who, while not evil, were considered hateful enemies of polite society. He did so much to work with the fey that they delivered an Arcane Mark to the paladin showing him as a friend to all fey. In session one of this campaign I introduced a homebrewed sprite variant called a Gravesworn Piskie that, as the name implies, represent the act of nature reclaiming a body after death and allowing it to feed the land.
The paladin died saving his entire party from a dragon, taking a heroic stand so that the PCs could retreat and regroup. On the spot where the body fell, an entire Tradition of Gravesworn Piskies suddenly appeared. they solemnly lowered the corpse into the earth, singing and wailing over the body as a mound of earth called a Faerie Bower appeared over the grave. While all Faerie Bowers in this campaign have a special ability to protect the body while it decomposes from being affected by necromancy, the paladin's grave seems unique in it's aura of power.
The party marked his grave with his own broken shield, using magic to etch his name into the steel. Spending a night within 30' of the grave enhances natural healing. What's more, novitiates and devout of Iomedae make a pilgrimage to the man's grave every year now. Completing the rite and spending the night by his Bower provides a clarity in discourse (Campaign Trait in my games adding +1 on Diplomacy which becomes a Class skill)
