When you start Dragon Age: The Veilguard, you're prompted to customise the Inquisitor. Not only can you alter their appearance, but a few select choices from the last game, namely who you romanced.
Light spoilers for The Veilguard.
There are eight people to pick from: Cassandra, Cullen, Dorian, The Iron Bull (Freddie Prinze Jr.'s favourite character), Josephine, Sera, Solas, and Blackwall. While not all of these characters appear in The Veilguard, who you choose does have a small impact later on.
As highlighted by Reddit user smolperson, the Inquisitor's partner will pen a letter to them while they visit Varric and the titular Veilguard, giving you an idea of how their relationship has grown in the last ten years. It's a cute little way to fold in their stories even if they aren't in the game.
Cullen writes a beautifully romantic letter to Inky, saying that he's "eager to see you" and that his love for you is "the most cherished constant of [his] life."
Dorian, who we do meet in-game (his redesign has even stirred up some controversy), still calls the Inquisitor Amatus in a poignant declaration of their devotion: "time and love are no longer things I care...