Good communication is the basis of effective project management. As leadership is about communication, you become a good project manager by communicating well, even without formal power
Most key project information is gathered first by the formal or informal project leader. Then you need to summarize, filter and report progress to all project stakeholders, including the project team.
By doing this, you have significant influence. If good progress is being achieved, others will be satisfied with your work. If unsatisfactory progress is being made, you need to provide factual information (not excessive detail, which enables others to look over your shoulder and start interfering) about the steps you are taking to recover lost ground. If you seek more resources to get back on track, then ensure all stakeholders are aware of your actions. Under-communication creates doubt and suspicion, so give a high priority to communicating with all stakeholders so they can’t criticize you for not knowing what is going on.
For example, if you have written a complex project document, call or meet with key recipients so they know the important parts of the information. Also, after a face-to-face meeting, confirm the decisions and follow-up actions with the relevant stakeholders by writing a meeting report. Document these decisions and actions, and send to the project stakeholders with a covering email in which you state that unless you hear back from them by a given date, you will assume they agree with what you have said in the document. To a great extent, your communication will be a key reflection on how you are perceived as a leader.
If you don’t have formal power, it is important to delegate responsibilities tactfully to team members and to document this clearly in progress reports, minutes of meetings, etc. Where a decision is above your level, refer it to decision-makers such as your boss. In cases where problems are being encountered, give your boss and other decision-makers plenty of notice of the problems so they don’t receive ‘unpleasant surprises’, rather than leaving such information until late in the piece.