Summarize:

One of the simplest ways to make a man feel loved is to directly tell him, “I love you.” A direct expression of love and affection may seem hollow when there are no actions to back it, but it is still an important sentiment to convey in words. It is the statement that focuses all your loving actions into one clear, obvious meaning. Mix things up. Saying "I love you" is important, but there are other sentiments you can use to express your love just as meaningfully. Try something like, "I'm grateful you're in my life," "I am so in love with you," or "You're incredibly important to me." For better or worse, women receive compliments about their looks and the way their bodies move from men on a somewhat frequent basis. Men hear these sorts of things less often, but as visual creatures, they usually like to know that you have your eyes appreciatively on them as much as they have their eyes on you.  For instance, if he plays a lot of sports and you usually go to cheer him on, tell him something like, “I love watching you as you play basketball” or “I love the way your body looks when you're playing.” If he is more of the artistic sort and is not physically active, you could compliment his body by telling him something like, “I love watching your hands as you play the piano.” Even simple compliments like “I love staring into your eyes” or “I could stare at your smile all day” can work wonders. Tell him that he turns you on. In strong romantic relationships, emotional love and physical love walk hand-in-hand. You need to express your love on an emotional level, but you also need to express it on a physical level. Telling him how much you love his body and love having it pressed against you is important. Of course, you can usually convey this sentiment with body language and behavior. As with emotional love, though, saying how you feel in straightforward words can be just as important. When the two of you are around other people, sing his praises. Talk about how great he is at his job, how passionate he is about his hobbies, or how great he is at making you feel loved. These are all great things to say to his face, but telling them to another person in front of him lets him know how proud you are to be at his side. Express your gratitude often and earnestly. “Thank you” should be part of your daily exchanges. Tell him how much you appreciate a kind gesture when he does something thoughtful. If there is something he has done for you habitually that you do not usually thank him for, go out of your way to tell him that you appreciate that gesture, even if you do not always say as much. Every couple fights. When you have an argument, be the first to apologize, even if you were not at fault. You do not need to be the first to apologize every time, but you should be the first to do so sometimes. An apology lets him know that he is more important to you than your own ego, and it also tells him that your relationship is something you want to fight together for. This does not mean that you should allow him to walk all over you. If you sense that he will never apologize to you without you apologizing first, or worse, see that he does not apologize to you even when you do offer the first “I'm sorry,” there might be an underlying problem in your relationship that you need to analyze and remedy. When life gets stressful, simply tell him, “I'm here for you.” He may still hesitate to show you his weak side, but telling him that you love him even when he feels weak can be incredibly reassuring. What you don't say can be just as important as what you do say. Serious problems in your relationship need to be addressed, but avoid nagging him, embarrassing, or making him feel ashamed for trivial reasons. A statement meant to shame is critical without being constructive. For instance, “You're so cold; do you even have any feelings at all?” would be a statement meant to shame. On the other hand, “I feel hurt when you walk away without telling me what's wrong,” is a statement that addresses the actual hurtful behavior and opens the problem up for discussion.
Tell him how important he is. Compliment the way he looks and moves. Let him know how much you want him. Brag about him to others. Thank him. Apologize. Remind him that you're on his side. Skip the shame.