This was an idea I had when I was only working part time and doing short term contracts. Seems like there is some demand for simple personal/business websites. Obviously applications like Wordpress are aimed at precisely this market and seem like the obvious solution.
To my surprise I discovered that there is a thriving industry of people who build websites using these applications for clients who are uninterested in learning to use such systems themselves. The only downside to the middle-man system is that the client has to employ someone else every time they need to make even the smallest changes to their site.
This is where my design comes in. I can build a simple site quickly with a few templates (just like WordPress) but I also design editable elements into the page that a client can simply click on and edit in place. This gives the client the best of both worlds: a cheap professional looking website and the ability to perform minor updates (images, text blocks) without employing anyone or having to learn how to build websites for themselves.
The editing feature is of course protected by user login. For this I use a small but secure login module I made myself that can easily be imported into a new project and can actually protect multiple sub-domains on the same server or even different servers.
I've also tied the editing system into git version control so all changes are saved and can be rolled back at any stage if necessary.
My own website (this one) has been the testing ground for this system and I've certainly found it very convenient for quick updates. This page and the linked element on the Projects page were built using this system.
(See that link there? The client can also include basic html inside elements if they like)