Let's talk about the things we don't say. The things that maybe we should say, the ones ripping our guts to get out, but don't appear. Maybe we're too nice, or polite or it's not the right time to say it. Or maybe we just haven't figured out the right way to say it, so it'll be understood for what we mean it to be. Who knows? There are as many reasons for us to not say something sometimes, as there are to speak. Sometimes more. Way more.
Imagine one of those times. Think of what it is you need to say.
Now, why can't you say it?
Write a poem where something remains unspoken. Either there's a messge that doesn't quite get out (play the subtext), or talk about the subject (hint at what needs to be said), or literally leave out pieces of lines (a kind of erasure poem in reverse... maybe you can self-redact?).
Conjure up the entire situation from the puzzle pieces you decide to share. Make sure you point out the missing parts. Build the mystery. Make the reader fill in the blanks.
Check out Noct by a certain Mr. Brendan Constantine.