I've read most of Guy's books over the years, and I love Enchantment. A small re-write and it could be a book about couples' relationships. In fact, it's so close, I'm going to draw a few comparisons for you, and then you can read his book and think about your beloved and notice the parallels for yourself. Of course it's a great career and business resource, so that's an added bonus for you.
Enchantment is the "Art of Changing Hearts, Minds and Actions" -- through delighting (being likable, trustworthy, etc.).
Guy even gives Enchantment relationship examples himself:
"Judge Your Results and the Others' Intentions . . . By the way, this is also very good advice for how you approach your results and your wife's intentions. The odds are very good that there are very good reasons for your wife's shortfall." (pg. 154)
"Drop Everything and Do What Your Boss Asks . . . This is also a good strategy for husbands. If your wife asks you to do something, drop everything and do it. You may not think it's important . . . You may think you see the 'big picture,' but you don't see her big picture (pg. 166-167)."
What I find so heartening is that Enchantment is an upward spiral; the integrity with which you embody and practice enchantment with your partner and vice-versa takes it out of "people pleasing" mode (potentially unhealthy), into genuine care and respect (healthy). We joke at our house: "See what you get for how you've been acting," as we give in some way to each other. We've replaced the negative connotation of that phrase.
Don't you think these questions and topics directly from Enchantment sound familiar in a relationship context?
What does this person want?
Is the change worth the effort?
Can I change?
How about these section headings:
Make Crow's Feet (i.e., smile genuinely, all the way to your eyes)
Use the Right Words
Don't Impose Your Values
Pursue Your Passions
Find Shared Passions
Create Win-Win Situations
Default to Yes
Enchant People on Their Own Terms
Be a Hero
. . . Need I go on? And this is just from chapters 1 and 2!
There's even a chapter on resisting Enchantment that speaks to making choices that are focused on your relationship: avoiding tempting situations in which you might make a mistake, looking far into the future for potential impact, and so on.
Chapters 8 and 9 are about using technology, so they might not apply to your relationship as much. I will add my piece of advice here, though. Do not let technology get between you. Anything with a screen is a potential relationship de-enchantment opportunity. A friend told me he saw a post on Facebook where a woman told her partner to duct-tape his device to his forehead so she could at least see his face sometimes. Ouch!
Oh, I found a couple more sections:
Tell Them You Want Them
Please, read Enchantment for the delight of your relationship.