The Cleveland Museum of Art currently has a Shinto exhibit displaying idols, portable alters, offerings, ceremonial clothing and embroidered silk screens. I am very fortunate to have seen it because it is the only place in the US that will have the exhibition. We were not allowed to take photos but there are several images on the CMA website.  Many of the items were still objects of worship on loan from Japan.

The various objects and the accompanying explanations of what they were indicated that the Shinto religion is embedded into the culture of Japan. The various warlords throughout the history built and supported the local temples and shrines. Great generals and lords were deified. Offerings and gifts were given to secure good harvest, success in battle or just to appease some of the beings so they would not cause mischief.

There were ascetic monks who practice various forms of self deprivation or exertion in order to conquer demons. Priests who danced, performed ceremonial archery or theater performances describing mythic events and heroes of the past.

All of this is far more interesting than the standard D&D cleric of Whosit God of War with a the same clerical powers as most other clerics with a few mechanical bits bolted on for differentiation. Things your religious leaders do should have a serious effect on the campaign world if the gods and other supernatural beings are active in your campaign.

An example: In my current campaign, the local druid was getting ready for the solstice sacrifices and the livestock to be sacrificed all became ill and died within an hour. The sacrifice did not take place because the omens were dire and the gods wanted the Great Druid to take the place of the livestock. Not being very keen on being the sacrifice victim of the day, he split. Now the whole region has been plunged into a drought that has ruined the grain crops, dried out the hay fields and pastures and is going to cause a famine over the winter. Merchants are scrambling to get more grain into the region, mainly to make a profit by gouging. The party has been asked to find the druid and bring him in alive so that he can be properly put to the knife. So far, the party has decide not to risk a fight with a high level druid even though they want to see him killed.