The most useful book that I've ever read about human relationships is "Men are from Mars, Women are from Venus". I attribute the insights of the author John Gray to the improvements that my wife and I have made in our relationship over the years. Yes, she read the book, too. Here are a few key points I pulled directly from the book:
1. The most frequent expressed complaint women have about men is that men don't listen.
2. The most frequent expressed complaint men have about women is that women are always trying to change them.
3. A man's sense of self is defined through his ability to achieve results.
4. To offer a man unsolicited advice is to presume that he doesn't know what to do or that he can't do it on his own.
5. Generally speaking, when a woman offers unsolicited advice or tries to "help" a man, she has no idea how critical and unloving she may sound to him.
6. Many times, a woman just wants to share her feelings about the day, and her husband, thinking he is helping, interrupts her by offering a steady flow of solutions to her problems.
7. Men need to remember that women talk about problems to get close not necessarily to get solutions.
8. When a partner resists us, it is probably because we have made a mistake in our timing or approach.
9. A man wants to make improvements when he feels he is being approached as a solution to the problem rather than as the problem itself.
10. A woman under stress is not immediately concerned with finding solutions to her problems but rather seeks relief by expressing herself and being understood.
Men are motivated and empowered when they feel needed...Women are motivated and empowered when they feel cherished.
I have found that these insights are very powerful for improving any man-woman relationship (they work with my mother, too

). I'm not sure if they can be applied directly to the problem of seeking a wife's support for a gender identity issue, but establishing a loving, trusting, supportive relationship in other ways surely will help when a disruptive matter like gender dysphoria needs to be brought out into the open.
I might add that after starting to take a hefty dosage of PM, I could feel that my emotions became sharper, and I had a strong need to talk to my wife about my feelings. This was a new experience for me, but I went with it. In a sense, I began to act more like a woman might in a stressful situation. My wife, being a woman, found it easy to listen and eventually come to understand my feelings. I think that dynamic was instrumental in her eventually coming to accept me as transgendered.
Clara