Keep It Simple
It can be hard to think of what to say to someone to let her know how much she means to you. Giving a compliment can be intimidating, as things don't always sound the same when you say them as they did in your head. A surefire way to appreciate someone special is to smile, look straight into his eyes, and get right to the point. The more long-winded you get, the more possibility for things to come out wrong.
Everyone loves to be complimented. Don't be afraid to compliment something you find unique, even if it is something small. Chances she will be delighted that you noticed a necklace or the cool way he cuts tomatoes. Noticing something small gives the message that you are paying attention to the other person. If you're not used to giving people compliments, think out what you'll say beforehand and practice it in front of the mirror. Notice if you tend to look away as you say the words; this denotes shyness or insincerity. If your compliment does not go over well, laugh and try again another time.
Saying Thank You
It can be easy to take your significant other for granted. In her book "Feel the Fear and Do It Anyway," Susan Jeffers notes that saying "thank you" to your significant other can be incredibly difficult. For this reason, one of the biggest compliments you can give anyone is to thank him or her sincerely for something that made you feel special. If your girlfriend or wife makes you dinner, reach across the table and squeeze her hand as you thank her for the special effort she put in. If your boyfriend or husband buys you flowers, tell him how special he has made you feel.
In an intimate moment, take the time to appreciate your loved one and his or her presence in your life. Saying things like "I'm so glad I have you," "You make me feel so good," and "You are such a wonderful lover" are less overt ways of saying "thank you" that still drive the point home. Telling someone how much he means to you may seem like a huge effort, but it does get easier with time. The first step is usually the hardest.