How to Make a Guy Happy:
Don't be b!tichy or naggy. You know how neediness and lack of confidence in guys reduce your attraction for them? Guys lose attraction to b!tchiness and nagging.
Stay in shape. Yes, do it for yourself first, but your guy will both respect you more and is more likely to maintain attraction to you if you are shapely. Men are visual creatures first and they are not sexually attracted to your brain DURING THE SEX ACT.
Learn the difference between joining him in hobbies/interests because he really wants to spend time with you versus he's just being polite. Sometimes, being with your guy during rock-climbing or something, will bring you closer. Other times, he really just wants to be in a traditional guys-space without his woman around. Some time away from one another is often healthy.
It is probably the case that you and he have different "messiness thresholds", that is, you are going to see a messy house/apt before he does. Take initiative to clean up what you want cleaned up without complaining to him. He may pick up on your behavior and help a little. Still, don't let this drive a wedge... it's one of those places where men and women have different standards and if you make him conform to your's it will come out poorly.
Don't use sex as a bargaining chip. Both of you should have regular access without game playing. Bang him good. If you have hang-ups, lose them. Surprise sex sometimes is a great turn on for him.
Don't expect him to read your mind and then get mad when he doesn't. This will make you more and more frustrated, but that will be your fault though you'll project it on him. Men are overt communicators and don't expect us to master the covert communications women specialize in. Did he leave his dishes in the sink again and that bothers you? Don't sulk around the house and not let him know why you're upset. Make it a joke, be lighthearted... if you are really unhappy about it, clean them up, say nothing while doing it, and then go over to him, kiss him, and say something like, "Dude, you and your dishes... like I'm training a puppy." You are not nagging, while telling him you were unhappy about something, took care of it, but communicated it overtly. He'll appreciate this MUCH more than covert message of sulking about something without telling him what the issue is.
Dress sexy/stylish for him. You WANT to look good for him. Even around the house, drop things like sweat pants and pullovers. If you are making an effort to look good for him, he'll appreciate it hopefully but if you do the opposite--let yourself go--he'll slowly resent you for it.
When he does thankless chores -- cutting grass, shoveling snow, etc. -- bring him something (hot chocolate, a beer) and show you appreciate his efforts. He's your hero and you should let him know that you are glad he's pulling his weight.
Tell him you love him when he's not expecting it. Say he's watching the game, make a little food (e.g., some cheese and crackers), bring it to him, set it down, go behind him, put your arms around him, kiss his neck, and say, "You know, I really love you", and then walk away and get busy with something else (or watch the game with him if you are into the sport). This will do wonders for you both.
Learn what hypergamy is and learn to recognize it in yourself. It will not guarantee you'll never be attracted to another man, but you can keep that in check. Us men are TOTALLY aware of our polygamy, i.e., we know we are sexually attracted to many, many women. But in a relationship, most of us most of the time keep that in check. Women, on the other hand, tend to not understand their own sexual triggers and when set off, they tend to lose control of their attraction to the new guy (filling him up with all sorts of traits he likely doesn't have) while downgrading their mate (which leads to less sexual attraction, nagging, etc.). If you feel yourself attracted to some alpha that suddenly enters your life, do what you have to do to minimize the time you spend with him (say he's a guy at yoga class... do NOT innocently go have a coffee with him after class... his intentions are not innocent). It is not your responsibility to never find other men attractive, but it is your responsibility to control that sh!t.
Also, learn what the rationalization hamster is. In short, women tend to act on current emotions and then backward rationalize their behavior after the fact. When you are about to do/say something, reflect if it has been filtered through your emotions or logic first. Remember, emotions are not knowledge and are fleeting. Think before you react, don't just react based on how you feel.
Don't revolve your life totally around him. Keep growing. Go to the gym, do yoga, take up a hobby, but whatever you do, don't stagnate.
Finally, go read the blog: adventures in redpill wifery
Good luck!