Saddle sores are miserable little boils that develop when bacteria enters an abrasion of the skin. These abrasions are often caused by chaffing or continuous rubbing of cycling shorts.
Even a small saddle sore can drive a cycle tourist absolutely nuts. What's worse, the cycling balms and creams typically recommended for recreational cyclists are not practical for the touring cyclist. So, what can you do?
Try several different types of cycling shorts. Often a seam on the chamois causes the chaffing. If you find seamless shorts or comfortable loose fitting shorts, go for it. Padded cycling underwear may also be a good solution.
Take off your cycling shorts as soon as possible after the ride. Bacteria is breeding down there. Get the off you body ASAP.
Wash them every night in antibiotic soap and make sure they dry completely before putting them on again. Rich has a pair of shorts with a real chamois that take two full days to dry (completely impractical!) Synthetic chamois dry much faster and breath better.
Sleeping without bottoms allows the area to air dry.
Lubrication with a cycling specific balm is not particularly practical for the cycle tourist as he is usually washing his shorts by hand every night and a balm can be a real bugger to get off without a machine to do the washing.
Seat position and bike fit: If the nose of your seat is too high it can cause chaffing on the inner thighs. If your handlebars are too close you may be sitting up higher on the bike than optimal, putting more weight on your rear end and less on your hands. Experiment to find the position that is right for you.
Standing up while pedaling a fully loaded touring bike takes some practice. When you are comfortable standing, do it often! Standing allow blood to circulate to the area and the air to circulate around as well.
Rest: We met three amazing women who were cycling from London to Sydney. They set their watch and took regular half-hourly rest breaks where they would dismount, gulp down some water and eat a bit. After meeting them we gave it a try in the tropical Southeast Asian heat and found it thoroughly refreshing. They never wore padded cycling shorts, preferring instead to callous their bottoms while wearing seamless crotched cotton shorts.
Preparation H. A cycle touring doctor we met before setting out on this trip told us this tip. Apparently, Preparation H is a skin toughener. While easing the swelling it causes the skin to get thicker and less susceptible to saddle sores.