I'm struggling a bit with this.
This is a process where users signup, and after that I need to present them with a splash page telling them that, in order to use the service, they need to do some action (in this case, send documents, and after verification, they get a key on their physical mail address, not mail).
Users still can access the admin area, they can perform a wide variety of actions, but they can't make the process go live until they finish the registration process.
While I can see the flaws in the current process, this is the only part that I can't change, so I'm left with a subset of actions to present the user, some of them can be logically dismissed, some can be optional.
The current approach
The legacy approach is to present a sliding modal, which works fine in terms of calling user's attention, although its copy is really poor and the messaging is kind of restrictive. Furthermore, it's easily dismissed, and as an user, I don't know what happened and why can't I do anything.
My proposed solution (so far)
Working on a stronger modal alert and keep inline warnings across pages/activities as well as an always visible "super header" in red with a warning icon and a link to the action required. Based in experience on other projects, this is a good approach and I think it will work fine (barring further testing).
While I have figured out the set of actions and elements, I really can't find a message that is informative as well as affirmative and engages the user to use the system, yet letting him/her know they need to perform an action. I'm leaning towards the user of iconography or a quick learning system with drawings. That would be no problem for us, but both the content and the copy are quite diffuse for me right now, really can't figure it out.
Note that while I have more or less an idea on how to lay out information, I'm open to suggestions, and I also understand that different content requires different visual approaches, so please don't be restricted by my proposed solution, because it obviously has issues!