How do you follow up a training exercise?

I've been training some colleagues in our intranet Content Management System this morning. It's a bespoke system, and generally works pretty well. Most people attending the training pick up the basics very quickly (in about 2-3 hours), and we provide them with sand boxes to play with their new-found skills. We also have a user guide, which, while it does not cover 100% of the functionality of the system, has been user-tested to provide an insight into the basics.

What I want to know is:

Is there anything else I can do in terms of follow up to ensure that this training sticks?

Contact me if you have any suggestions