If you're the type of person who finds it frustrating to spend more time correctly naming a rig than you spend drawing the joints, then meet your new best friend, the naming tool.
On the one hand, working with a correctly named rig can often slow you down. On the other hand, it can make it easier later on to find your way around. Or perhaps you work for a studio that uses a particular naming convention. Or you're using other software such as MotionBuilder in your production pipeline that requires a particular naming convention to be used, otherwise it won't work. In these cases, the naming tool can make the changes for you.
For example, it's a snap to add a prefix (hand becomes left_hand) or postifx (hand becomes hand_left) to a hierarchy that's already been named. Or you can replace part of a name with different text (left_hand becomes right_hand).
Best of all, you can save an already correctly named hierarchy as a preset and use it to automatically name any new hierarchies you create that have the same structure. This works all the way up to complete rigs, provided both hierarchies have exactly the same structure. However, to keep the tool as flexible as possible, you might want to create several presets, with each preset defining the naming for a particular part of the hierarchy, such as an arm or leg. There is no need to create separate presets for each side of the character. Instead, simply add a prefix or postfix to the preset when you use it.
Although this tool has been developed especially for naming character rigs, it can also be useful for renaming other types of object hierarchies.