Non-sexual social nudity.
There are a lot of reason to go naked in the presence of others. Widespread body shame is perhaps the most significant. There are (at least) two significant cultural streams in play in Western cultures (found in others as well though), both of which are contrary to healthy Paganism. They barely need discussing, but are worth mentioning: 1) deep-seated, sexist religion-based sense of modesty, and 2) a narrow sense of physical beauty driven by a highly commercialized and celebrity-based culture.
I could go on and on about the psychological dynamics of both, but instead, the main point is this: if being naked in the presence of others makes one uncomfortable, for any reason other than atmospheric conditions, then one is seriously out of touch with their own personal nature, and the nature their species on the whole. From the perspective of the Contemporary Paganism I envision, it's a spiritual illness that a good Pagan lifestyle should cure, and if It doesn't, It isn't fulfilling Its primary functions.
The main reason it isn't necessary to dig into the psychology of how someone came to feel body shame in the first place is because the cure doesn't depend on understanding that. In fact, that's a deep rabbit hole and the answer to the problem will never be found in it, no matter how long one digs at it. The fix is much simpler, though it isn't necessarily easy: desensitization.
Find a safe physical and social environment to go naked around others and do it regularly. Keep at it till the uncomfortable feelings cease.
The most challenging part, initially, is finding a truly safe environment for doing it. A healthy local Pagan community, the one I envision and that these threads are about at least, would be the ideal place to go. In a perfect [Pagan] world, or so I imagine, a healthy Pagan community could do more than provide a safe space for overcoming body shame; It could provide real support and reinforcement for taking on the task as well, which would likely speed the process for most people.
We come in all shapes and sizes, we wrinkle and sag as we age, etc. It's the nature of our species. Healthy Pagans should celebrate such things, as a sacrament. If there's such a thing as Pagan sin, trying to hide or hide from ones own true nature must be one of them.