Here's a link to a very insightful post from Last In - First Out regarding the best-practices of systems management.
It deals with Ad-Hoc Management versus Structured Management, and it's full of outstanding advice.
Read it for yourself.
Too many times, when we're the only person responsible for this sort of thing, do we overlook the "proper" way of doing things because of lack of time, lack of motivation, or lack of knowledge. There's no shame in any of those; they're all hurdles to be passed on the way to more reliable infrastructures. Even if you're the only one who creates accounts, and it's going to take a chunk of your time to develop the tools to administer accounts across your network, that's time well invested. If you're lucky enough to some day get more help, you want a structure in place for that new person to follow, and in the end, even if it's just you, having these tools will allow you to use your time more effectively.
I certainly can't claim to have instituted all these suggestions, but it's definitely something to work towards.