Project Management is about continuous learning. Whether it's related to changing technology, production practices or client management, a Project Manager will never stop absorbing new information. As a PM evolves with their career, there are a few fundamental skills that will be required for survival - skills that will help mitigate the most severe risks and the most trying clients. Unfortunately, not all Project Managers will be 'naturals' when it comes to these fundamentals, but effort and practice can go a long way to honing this arsenal of ability.
Finesse: OK - this is the most difficult and intangible skill to describe. In this context, it refers to the delicate, nimble management of people. People can be clients, production teams, external vendors, or your employer. A Project Manager will need to finesse each of these people at various points throughout a project life cycle for different reasons. Being able to finesse can help develop stronger relationships, trust, credibility and a sense of competency. Most importantly, a Project Manager will use finesse to continuously focus people, keeping them on track towards objectives and deliverables. Project Managers who are great organizers but poor finessers will fall short of the mark. People skills are an absolute requirement - particularly when dealing with difficult client management issues.
Time management: Without this skill, a Project Manager may as well throw in the towel. The job itself is about managing time for large groups of people over long periods, working towards an end deliverable. If you are unable to prioritize and manage time, you will struggle with your own workload, and fail at delivering projects within expected time frames.
Multi-tasking: I've written about this before because it is part and parcel of any Project Management role. The secret is in prioritizing and focusing on a single task at a time, regardless of how long your to-do list is. You can learn some tips about multi-tasking in this blog entry.
If you're able to fine tune these three skills, you will be better equipped to tackle any challenge you face. Your confidence will increase and your clients will appreciate your capacity to manage their business. Most importantly, these are skills that will help in your own life and in any other career you choose.