There's no one "right" way to deal with it, for starters. People will give lots of advice and describe a bunch of scenarios but don't feel like you "should" do it any particular way or that you're doing something wrong if you grieve in your own way.

For me, I "talk" to my dad now and then. It's been six years now and I still find comfort in doing that. I'm an atheist, I don't believe he's actually hearing me, it's just a thing I do that feels nice psychologically. I've been imagining I'm keeping him "up to date" on stuff, since one of the things I told him on his deathbed was that I'd let him know "how it all turned out" - he was always future-focused and I'm sure it annoyed him that he wouldn't be around to see it.

I wouldn't worry too much about any deep and meaningful "final words" and such, though. I think the words that were exchanged throughout life were just as important, if not moreso.