Soy sauce isn't very frequently used on its own. It's usually mixed in with other ingredients to make sauces or to flavor dashi, the traditional broth base. Mix soy sauce and vinegar with some chili oil to make a gyoza dipping sauce. Mix it with mirin and some sugar to make teriyaki sauce.
Super Sushi Ramen Express, by Michael Booth, is an interesting read for anyone interested in Japanese cuisine - or just cuisine in general. He cited Kamebishi as the only company still using the mushiro method, which I think is the original way to produce soy sauce. Their whole process takes a minimum of five years. He says it's the world's best. It's on my list of things to try. They are also the only company to make an aged soy sauce, which was inspired by the balsamic vinegar producers in Italy. Apparently a 10-year aged bottle costs about $150.