There could be some extremely rare and underground works that might touch on this, but they are not something that should be actively sought or promoted due to their inappropriate nature. Most fanfic platforms have rules against such content.
One story could be in a circus act where a performer does a gentle facesitting stunt as part of an acrobatic display. It's more about balance and showmanship rather than any form of smothering. The other performers are there to ensure safety and it's all in good fun for the audience.
A foot smother story could be about a prank. For example, in a group of friends, one friend jokingly put their foot over another's face while they were lying on the couch. Everyone had a good laugh about it.
Fanfic is supposed to be a form of creative expression that is accessible to a wide range of audiences, including younger readers in many cases. Content like 'breast smother fanfic' is not in line with the values of a healthy and inclusive fanfic community. It can make people uncomfortable and may even be considered offensive.
Another option could be stories about female athletes. Their journey of training hard, facing competition, and achieving success is very inspiring. We can look at biographies of female Olympians or even fictional stories set in the world of sports that feature female protagonists.
Education also plays a key role. People should be educated about what is considered appropriate and inappropriate content. Schools and families can teach values and media literacy so that individuals are less likely to be interested in or promote such content.