FH and I do not live together, but are together most evenings after work. I have developed a theory. Most nights he is at my place until I fall asleep and he always "tucks me in". He says good night, sweet dreams, kisses me, and turns out the light. That kind of stuff. On the nights he does not do that I never sleep well. I'm convinced they are related.
Do you and FH or DH have a bed time routine? If you don't do it, does it make a difference?