I read a book a few years back that had some interesting things about couples and sex in it.

The title of the book was:

The Great American Sex Diet: Where the Only Thing You Nibble On... Is Your Partner!

The overall take-home/take-to-bed value that I recall was that couples should be "consuming" each other three times a week (at minimum).

One time, she chooses, One time, he chooses, third time they choose.

This worked really well for my husband and I as a way to "bite back" against all of the time and energy consumers in our marriage/married life with kids.

I found that on the days where it was "my time" to choose that I would spend HOURS thinking of sex and what I would do the poor guy and vice versa.

Actively taking charge of our sex life was liberating and it was exciting to recognize that we had a choice of when, where and how and how long - the only choice we didn't have was the choice as fully functioning adults to deprive each other of ourselves by not actively participating in one of God's gifts to marriage.

(Also recommend "The Proper Care and Feeding of Husbands" by Dr. Laura Schlessinger and "His Needs, Her Needs by Dr. Willard Harley, Jr.)