In the course of world building the decision for what, if any, gods to include in the design. Do you use the ones from a published setting? A mix from multiple sources? Do you create your own?
I have done a mix of all three, though the ones I enjoy are the ones created whole-cloth by myself or in collaboration with players. One such deity whose name is indeed long forgotten (did it begin with Ch?), represented the domains of Vice and Humility.
Vice and Humility may sound like an odd combination, however the common mantra spoken by 'experienced' members of the faith is "a person must fall before learning to pick one's self up", which seems to briefly sum up the idea.
Devoted adherents are typically those who have drank, gambled, and/or whored their way to their personal and financial downfall. A good many end up spending at least some time at the church monastery performing humbling labors, wearing garments of hand mended sack cloth, and eating the most basic of foods. Some remain, having found either the need for the security blanket of the monastery, or having heard the calling to aid the newly fallen or to tend to the 'fall' of those not yet at the bottom.
Those tending to the fall perform their duties visiting places of ill-repute and observing the patrons, looking for those nearing their point of breaking. While watching for these seekers, the brothers and sisters gather donations, offered to them without prodding by those trying to curry favor from the deity, hoping not to fall.
In cities that have not embraced the deity, Humble Elders, pose as homeless and misfortunate, never asking for money or food, though often receiving both from the generous or those who know who these faithful serve and seeking favor. While performing this mission, the Humble Elders watch and listen for the opportunity to quietly minister to the fallen and soon to fall, eventually gathering enough new faithful to begin a monastery.
The core tenets of the faith neither condemn or condone vices, merely acknowledging the role vices serve in enlightening the populous. There is a branch of the church which the orthodox refer to as the debased, filled with hubris. The debased have begun to involve themselves in the operation of taverns, gambling houses, and brothels, with the potential to garner great wealth, and sometimes leading them into conflict with criminal syndicates, and the authorities. Those who leave the church or have become debased, may fall again, and would be welcomed again as newly fallen.
The typical fallen or faithful is a human male, though females, and other races are not immune to vice or the need to find humility.
Different monasteries may have different holy symbols if any at all. The deity has no specific weapon and adherents forced into conflict use whatever comes to hand. Some may be considered proficient with an item they used in a profession if it is available, like a blacksmith with a hammer. No specific colors are associated with the deity, though brown, gray, and other motley are the most common.
The deity is often depicted in a ragged cloak with hood pulled up, face in shadow.