With the twins, things were easier. A combination of more experience under our belt and the fact that they were together in the same room. I don't exactly know when this particular ritual started or how but it works, so we've just kept doing it. And will for as long as I can because it is just too precious.
Every night, I have to tuck them in, make sure that they have some water on their nightstand and say/do the following in this particular order, no deviations allowed:
"i love you"
I walk towards the door, turn off the lights and say as I close the door "see you tomorrow"
and that's that :)