What can we do to bring water loss from breathing down to the absolute minimum possible?
Techniques or devices useful to adventurers with no frequent water access is what I am looking for, such as hiking or biking across a desert for longer than is reasonable to carry or find sufficient water.
Water does not necessarily need to be reclaimed by drinking. Any answer for which water that would be otherwise lost due to breathing but is in your body keeping you healthy instead is a good answer.
See also: "Is drinking urine safe?" (Short answer: No) Urine is another one of the biggest sources of bodily water loss, and you can distill it back into pure water with a small amount of resources and a sufficient heat source.
Food for thought: I recall that in the story "Dune" the people on that desert planet had access to wearable water reclamation equipment which reclaimed almost all of their water, not only from breathing but other sources as well. Dune is science-fiction, but it does make me wonder if such technology is actually available in reality; is there any easily portable equipment that can reclaim a significant portion of breath water in the same way?
This question is inspired from reading this answer to a question about water rationing and death from dehydration. From that question, and reading up on the topic elsewhere, it appears a reasonable portion of water lost per day can be due to water vapor lost in your breath. This can even be a significant portion of water loss in some environments, such as cold dry air.