Shadowheart: There are a few (I think 4) triggers in the maps that give persuasion opportunities. The dog and owlbear cub help too.
Astarion: He is basically a "playboy". I have one play through that left him in the camp 100% and still has conversation opportunities pop up, before celebration. Basically you have to kill enough stuff. Oh, you have to discover his vampire secret though.
Lae'zel: If you pay attention to her dialog with Wyll, she don't believe in love, but open to bed.
Gale: As long as you feed him all the expensive stuff ...
Wyll: Side with tieflins and kill enough goblins and he is yours.
So on the night of celebration ...
