The container you select should be of an appropriate size, both for the environment you've chosen and for the contents of the cache. It should also be waterproof and weather resistant, as caches are almost always constantly exposed to the elements. Anything you put inside the cache should be in a zip-top bag. Sensitive items, like logbooks, may need to be double bagged to protect them. Think about the environment your cache will be in -- areas that are subjected to below freezing temperatures or periodic flooding may require additional consideration. You need to label the container so that casual observers and geocachers know what it is. Labels should indicate that it is a geocache and include your contact information. Some geocachers also include a brief note explaining what a geocache is in case a non- player finds the cache.
When you are ready to put your cache in its hiding place, you should take several GPS receiver readings to determine the coordinates for the cache. Write the coordinates on the cache's label with a permanent marker. You should also include the coordinates in the cache's logbook, and don't forget to write them down for yourself to post online later.
After you get back from hiding the cache, you'll need to report it on a geocache Web site. You'll need to include the coordinates for the cache, what the container looks like and any necessary hints (such as where geocachers should park their cars before heading out on foot or signs to look for when searching for the cache itself). Most geocaching Web sites include a way for geocachers to get in touch with you, but you may want to include an e-mail address just in case.
Geocachers who hide their own cache must maintain it if they want the Web site to continue to list it as a viable cache. Over time, you may need to replace the container or add a new logbook if the old one is getting full. You'll also want to take a good look at the environment around the cache to make sure it isn't being adversely impacted by visitors. If you feel that the surrounding area is suffering, you should remove the cache and report it as being offline.
In the next section, we'll look at the sort of things you can find (or put) in a geocache.