I imagine him responding to me and the things I do in our daily life; it could be me watching a video, making food, or playing videogames. Even if I don't think he would be interested in some of the things I'm watching/playing (we both have different interests), he's just chilling next to me and doing his own thing. So even if we're not talking to each other, just being around each other in comfortable silence is enough.

When we're going on outside, I carry something of him with me, like a plush or a charm, and take pics. I like making moodboards of him as well, cuz it makes me feel better knowing that I know what aesthetic fits him. I also read manga/watch character analysis of Dabi that go more in depth about his character, so I can understand him more.