Far No idea if this would work generally, but last time my DP was too tired, I gave him sympathy, we went to bed, turned out the lights... and I quietly sighed and said I was feeling all turned on. He decided he wasn't soo tired after all...
Jazzy when you sign up to fertility friend they send you an email 'course' for a week I think. Teaches you about all the hormones and signs, and how to chart your temp and check your CM etc. I found it informative and useful, though I knew a lot of it already, I hadn't really learnt about the 'science' background - what hormones are active when, and how that influences your cycle.
I think I'll start taking multi vits again this month, and for the DP too. We took them for the first 6 months, but weren't really sure if it was making any difference, and it was expensive to buy them all. Takes a few months to work though right, so if I buy them now I should get myself an ironic BFP.