Ask HN: Communication security. How would you?

I want to piggy-back off of the email/security discussion with today's earlier thread about autocrypt. I am not looking for a how-to list. I have my opinion's on what should be done and what should not be done. I would like to see what other's think (and would do) considering the following.

Let's assume that:

- I am important. - I need to talk to undesirables [1]. - I need plausible deniability.

[1] Undesirables being people that someone in a job, the public, the courts, law enforcements - really anyone that you can not talk to without having a negative connotation attributed to you.