In the full organizational set-up of a PR agency, a team working on one account, (proportional to the size and requirements) could have anywhere from two to five members, each tasked to handle essential areas, typically: account direction, account management/servicing, editorial/writing, media relations, and monitoring.  The other areas, which may not be needed on a daily basis, could be assigned to any one member of the team, or more cost-effectively, out-sourced to an expert.  This would normally cover event management, messengerial/courier, and accounting work.

Even if you have been trained more in any one or two specific tasks, it always helps to be knowledgeable and experienced in all areas of PR.  This will greatly benefit you if you want to work independently or freelance, as in my case.  I've found the top five skills that can help you on your way to autonomy are:

1. Oral communication skills.  You should be able to express yourself well verbally to different types of people, boss or otherwise.  You should also know how to maximize the skill for presenting, because a huge percentage of your bagging an account or communication project lies on how well you deliver your pitch.
2. Written communication skills.  People usually assumed everyone in PR could write.  But just as not every writer has good interpersonal skills, it's should be acceptable that not every PR account manager or director could write.  If you could write, it would save you the effort and time spent on briefing a writer on the editorial requirements, and consequently, shorten the work flow or process, and eliminate some expenses as well, by a considerable amount.  Writing well could also help ensure correspondence is never misinterpreted.
3. Accounting. Doing the math yourself is handy from measuring media mileage, drawing up projections, cost estimates, and billing statements.
4. Media Relations.  Speak well, write well, mean well -- you're halfway there.  All you'll need to do is know your target media. So do your research (see next).
   
5. Monitoring.  How will you know what media venues to recommend, what strategies to propose, what tactics will work,  if you do not read, do not watch TV and movies, and however else you can monitor trends?

PR is not as simple as possess-all-5-skills-will open-PR-firm.  But, if you do find yourself proficient and effective in all 5, you're equipped and competitive enough to handle a project and/or an account and not worry about overhead.