Meditation & Shamanic Rituals

Shamanistic rituals and Mediation has been lumped in here as there can be some crossover between them, at least on a superficial level. Both use a series of pre-conceived & pre-ordained methods found in many religions around the world. One of the main beliefs is the idea of connecting to the world around them, the ancestors, spirits of other kinds, and / or the gods at the heart of these practises. In some cases drugs are used, in others none.

History

Many sapient species have had or still have priests, shamans, witch-doctors and the like, as well as specific monks for some. Many have had  the same experiences as the younger races, and indeed, the latter has learned much from the elder races.
Such practises can also be learned, usually by trial & error or by the guidance of powerful beings such as deities or ancestor / nature spirits. Most of these have been developed and spread by early peoples as they spread out from their place of origin, taking the practices beyond the place they initially rose. From there they adapted along with the peoples practising them, whether by encountering situations, creatures, or circumstances that led to changes occurring.
In a few cases, two or more different sapient species crossed paths, and their practises either intermingled or split apart further. For the former, the Elves, Dwarves, and Germanic Humans (especially the Scandinavians) intermingled to quite a high degree. Cases like that has led to a situation that each species is almost indistinguishable from one another until closely examined and minor divergences appear. Even then it can be quite hard to tell. The same has happened to a degree in the Far East with the worship of Dragons, that it can be hard to tell the differences between Asian Human belief, Dragonborn, and to a degree even the local Kobolds.
In many regions, the need for food, shelter, protection, and localised phenomena has led to the original beliefs changing. Also the creatures encountered, and the challenges of surviving against extreme conditions have all led to some degree in changes, as well as the language of the practitioners.

Execution

Many such practises involve the need to gain insight to linking with a perceived 'godhead' or spirit. This usually involves entering a trance in some way, or invoking the spirit to enter a specific object or mortal present. It can even be as simple as reaching into oneself and achieving a sense of clarity or oneness within. Some are done with others looking to do the same, so each can effectively learn or strengthen each other, helping to focus their minds to a higher ideal. For others, solitude & a set place or condition must be met to allow for this. In some cases, a whole tribe, clan, or community needs to be present to fulfil parts of the rites.
Chanting, praying, singing, specific body movement, dancing, playing musical instruments, taking specific natural drugs, are all part of it. Depending on the specifics, some find the best way is to concentrate, in peace & quiet, while others it is a rowdy affair where the community reaches a peak of religious ecstasy, that allows the shaman to draw in the power & fervour of others. Many different practises have came out of this, and some, like the Far East monks, have highly religious & set standards that allow them to meditate for hours on end, and control certain natural energies. Indeed, many clerics are heavily involved beside just what would be referred to as shamans or monks, helping to direct what is essentially the extreme forms of worship present.

Components and tools

Many shamans, religious leaders, and those practising meditation, use a number of different components & tools. Most are standard throughout, and can vary by type. A few unique items may be used too.
Musical instruments are commonly used in many rites. These involve drums usually made of wood, and either animal skins or similar material. Sometimes flutes or other basic woodwind instruments are used too or in place of the drums. Cymbals are sometimes used as well.
Incense can be used in the Far East & Middle East religions to stimulate specific senses. Other aromatics can be used at times in other practises.
Quite a few will use dancing, singing, chanting, and/or narcotics to enter trance state or open up to the spirit world. These can also open up the participants to altered states of consciousness and talk to the ancestor spirits, nature's spirits, spirit guides, or one or more deities.
Some use spells and/or prayers in place of or in conjunction with singing and/or chanting.

Participants

Depending on the society the participants can range quite a bit. In some, like the Far East, monks & nuns form cloisters & temples, usually with an ordained priest in charge. The elders / most experienced would set the routines, and codify how & when rites take place. Regular meditation whether singly or in groups & how enlightenment is achieved varies somewhat, as well as what happens before during & after it happens.
Some like the Brahmin of the Indian States follow similar patterns to the far east, though a few follow far more esoteric methods, including using narcotics, and rituals involving taboo subjects depending on which deity is being worshipped.
Religions such as Christianity, Islam, and Judaism has their specific methods & beliefs.
Shamanism is the most varied, with nearly all forms being used in one form or another. It falls on the tribal group of what applies as ritual shamanism, and can vary quite wildly in some regions. Many of them have a history of the local spiritual leaders carrying out the necessary rituals, and designating what path the rites take according to the whim of nature, deity or deities, the spirits, or any number of specific details. Sometimes the highest ranking individuals in these societies help out or partake too as an example to the others they lead. Sometimes a whole tribe or settlement will take part as when it is deemed important, and the leader of either settlement or the eldest leading the way in worship. Many cults can come about in these societies, an example being the berserker cults, and others trapped on the path of a specific form of worship.

Observance

Again, this is as varied as the forms of worship that exist.

The shaman sat cross legged in the middle of the circle of stones. After taking in some of the smoke from the sacred fire sprinkled with poppy seeds & cannabis leaves, he started to chant in an unknowable language. The others of the tribe started to gently bang their drums, or slowly dance around the circle. Eventually the smoke filled their lungs too, and they felt the pull. The spirits of the ancestors called, and they could feel the living spirits of the animals nearby call, trying to tempt them away into the nearby forests.
Each felt the pall of darkness that the ancestors had warned about before. Each was aware of the growing darkness, when the Wyrm in White unfolded it's wings & flew south. Such a thing had happened recently and each were aware now, that something far worse lay below in the caverns of the mountainous home of such a creature. It's call has been getting stronger now, more so since the Wyrm left a few hours ago. Exactly what this thing was, no-one knew, not even the ancestors.
There, deep inside in the visions, was a monstrous primeval force awaiting for adoration to come it's way. A pull that lusted after power, that had seen the old & new races were ripe for plucking, and devouring spiritually.
The elders, and especially the shaman, had been aware enough to put up magical shields, and all they needed now as to check on the ancestors. Make sure their defences in the other worlds were safe. Asgard, Alfheim, Svartalfheim. All these needed a boost too by the living in Midgard. All it took was for such a being to get a foothold in these others and this monster could latch on to it, spread the rot into Yggdrasil from multiple angles. Thus the shaman called on the tribe to participate in this, bolster their ancestors who roamed golden halls, and protect one another.