I've done almost all my geocaching with (mostly) two rules:
1. Don't drive between individual caches.
2. Look for at least three caches during a cache run, either walking or bicycling between the individual caches.
It's fun, great exercise, and it works for me. I hope to add kayaking to the list of modes of transport between individual caches.
My major problem when doing this is which cache to 'favorite' when I've had a great walk or ride between ho-hum caches that were only interesting because of the walk or ride. If the caches didn't exist, I probably wouldn't have had the experience, so I'd like to express my gratefulness somehow. It's especially perplexing during a series of caches.