For any project, the most important part and, indeed, the area almost always identified by project managers and management as needing improvement is communication.
Communication between team members, communication between the billing department and suppliers or subcontractors, communication between upper management and the project team, communication between management and outside stakeholders, communication between the construction bosses and inspectors, communications between your company and the surrounding community…..you name it.
Communication to all major stakeholders not only keeps people up to date on your project's or company's progress, but it also helps create that all important buy-in and ownership of project or company decisions.
Just remember however that, although communication is your key to success, no one likes to be spammed continuously with information they don't care about or need to know. Indiscriminant communication not only irritates those receiving it, but can also dilute your ability to get what you need from people when you need it, because they no longer read what you send them because so much of it has nothing to do with them. So, after you make that extensive, team-generated, communications list, sit down and look at it (with the team), think collectively about the risks of one person or another not knowing something important and the impact it could have on your project, and then prioritize the people on that list.
This will help you and your team to identify who has the capability and highest probability of wreaking the most havoc on your project if they are not adequately informed. Sometimes the results of this kind of analysis can be quite surprising and you find people you might not have thought would have such a huge impact as they do!
You will also find that some of the people on the list you thought might be important are less critical than you initially thought. Obviously, keeping the highest priority people informed of the project, its status, progress, and problems is going to be your project's or company's key to success.