Being a late starting actuarial student gives me many years of previous work experience, the first five of which spent with one of the top management consulting firms. There, preparing memos and giving presentation to transform complex analyses into convincing action items is the daily job, so communication is a BIG deal.
My key lesson learnt there was that hardly anyone is born a great communicator. It takes a lot of work and exercise to become one, but with commitment most people can get very good results.
My Firm invested heavily in communication trainings, had a large number of my presentations individually analysed by staff in the Communications Dept (yes, there is one), funnelling my messages into a proper structure and removing redundancies, choosing the right chart type for each message, and ensuring each slide was in perfect format (describing spacing, font type, size, underlining, colours, etc for every possible situation). My key presentations would be reviewed by peers and seniors as well. I also spent time with actor coaches preparing to address larger audiences. I must say I never came across this level of commitment to communication in any other industry.
IFoA tries to make actuaries better at communicating, which is right, but the current CA3 exam is a bit of a whitewash. While it does say some of the right things, it is a long way from being a full blown communication course, the quality of the material is questionable and it lacks feedback. Failing to show the mistakes leaves the job unfinished, hence many of the comments here about actuaries being "on average" good at communicating but the exam failing to recognise it. With all due respect, in my experience actuaries are not that good at communicating, particularly to non actuaries, and many don't care.
There is no substitute to the level of coaching I was describing above. The best surrogate for that is to prepare the CA3 exam in pairs or small groups and have your work revised by other students, if not tutors. This is not an exam that you can easily self assess.
Maybe, without fully redesigning the course, IFoA could put candidates in groups of 2-4 people and give them some joint assignments and an opportunity to receive feedback from each other before the final individual exam. Similarly, ActEd could provide a similar pairing service. Sharing essays is easy. To assess presentations, there is free software like movenote.com to upload videos and slides side by side. It would be easy to share a link and receive feedback from other students, maybe conditional upon reciprocity.
I am soon to go for my first CA3 attempt. If I fail it I may have some time to work on this.