Imaculata
Hero
One of my favorite moments of immersion occurred when I wasn’t even at the table. The PCs had dropped anchor for the night, and were gathered around the table talking. I got up and took a break to stretch my legs. When I came back, they were still talking in character.
That happened to me recently as well. We took a short break to fetch some junk food, and while over at the restaurant they continued in-character, because they were so into it.
During that session we also had a great moment where I played the part of one of the female npc's, and she explained just how utterly terrified she was after what the party had witnessed in the realm of the dead (and then shown to their crew with cantrips). I noticed that a massive silence just dropped as everyone was totally into it. They really felt for her, because they understood why she was so scared for her life. I usually try to keep things light-hearted and fun, but sometimes the plot calls for some drama, and when it hits it hits those feels hard.
It is great when the players are really immersed in their characters, and in the world. And my last session was dominated by such great immersive moments. It also motivates the players to do some awesome role playing, in my experience. Give them a world that feels immersive, and they will immerse them selves in their characters more.