A number of us are suggesting different solutions. I believe they are all different parts of a puzzle. Different spouses will respond to different solutions and different phases required different methods.
Some have advocated the hard method: a (figurative) slap in the face, shock, confrontation, ultimatum, etc. I can see the necessity of that in certain situations to shake the other half out of their complacence.
To me the hard method is to reboot the relationship. To get off the slide and start rebuilding the relationship. To get all hands on deck to steer the (relation)ship.
Once the other party has been "awakened", the hard way cannot continue. I'm sure we prefer to be making love with (i.e. two-way) someone who enjoys the act rather than fucking a dutiful but reluctant dead fish. Besides, it will wear on the relationship and make things worse in the long term.
The couple needs to start working on the issues of the relationship that are getting in the way of intimacy, not just physical but emotional as well. People don't just stop enjoying sex for no reason. There's usually some other issue in the way. And for many women, emotional intimacy affects physical intimacy.
I've advocated counselling. It may work for some, it may not for others. Its just one of the avenues available. There are many more: like marriage repair workshops, support groups, etc. What's important, I've learnt in my journey, is that both parties must recognise there are issues and want to fix the problems, then seek the resources to fix it.
Too often people go into a complacent mode when the marriage has gone stale. Adopting a wait and see or a "that's life" mode, thinking they just have to tolerate the remaining years. I even have friends that were simply waiting for the children to be old enough, before asking for divorce.
What if the other half refuses to fix the problems? I do not think its a complete lost cause. In some cases, yes, its gone. But in some cases, perhaps not. The half trying to fix issues has to at least persist for as long he/she can. Of course, there must be point where it has to be abandoned, but if he/she never try, he/she'll never know. I have a friend who got caught cheating twice, and his wife left him, taking with her their young son. He repented and has been working for at least 3 years trying to win her back. Over the years I have seen him slowly succeed, baby step by baby step at a time. Today, although they are still living separately, I believe a reunion is not far in the future. Now he sends/fetch them to/fro school/work daily and go on family outings on weekends. When I met them recently, they behaved like a loving, intact family.
Then, we've got some husbands saying, I do all the housework, take care of the kids, make sure she gets enough rest, etc, and she still refuse to show me love. How come I show her all this love and she is still so unloving. The reason is she is not feeling loved. Knowing you're loved and feeling you're loved are 2 different things. You need to speak her "Love Language".
This is the theory by Dr Gary Chapman. He writes about his theory in his book "The 5 Love Languages". It is a easy book to read, not very chim, and most importantly, makes sense. Non of the small print psycho-babble that some books are. It's not going to solve all your problems, but I strongly believe its one of the essential tools you should have in your relationship toolbox.
Briefly, the 5 love languages are: Touch, Acts of Service, Words of Affirmation, Quality Time and Gifts. Each of us "speak" 1 or 2 of the languages. We naturally express love in these languages and feel love in this languages.
"Touch" people express love through physical contact like holding hands, hugging, cuddling. When someone holds their hand, hug them, etc, they feel loved.
"Acts of Service" people express love by doing things for their loved one. Like doing housework, running errands, cooking for them, etc. Similarly, when people do things for them, they feel loved.
To make our partners feel loved, we need to learn to speak their love language. If your spouse is an "Acts of Service" person, learn to do things for them. Make effort to do things for them when they ask you to, and not just procrastinate.
You can read about the rest at the web site, and the whole thing in the book.
I know some people will be sceptical about this love language thing. I don't blame them. I was too, initially. But I read the book and it really made sense to me. Try the online assessment of your language here:
http://www.5lovelanguages.com/assessments/love/
Focusing back to making love. If we want to make love, we need to make sure our other half enjoy sex. One bro's wife says he is like a pervert. One sis shared that she dreaded sex with an ex-bf, but enjoys it with her husband. What's the diff? One didn't care how she feels, just poke and go. The other made her feel loved, comfortable and relaxed. So once your other half is ready to try sex again, start finding out what she wants or needs to feel comfortable with sex again. What has changed from the time she made loved to you daily to the time she stopped. My ex told me she could not reconcile being sexy and being a mother at the same time. Another girl told me kissing is important to her. Some feel like a sex object. Etc.
Sex in a marriage is part of the whole package. Not just a "duty" or "responsibility". It has to be handle as part of the bigger picture and not just by itself.