It is powerful how a few words of praise can truly change things.
At work I use praise to motivate writers to blog more and take on new assignments. My emails of praise are no more that three sentences in length, and the most expressive word used is "great." Yet recipients usually are so thankful to receive them and are immediately motivated to work harder.
The trick is that the compliments are genuine - I look for the positives, big or small, and praise them.
I am learning that compliments are just as powerful in my relationship. Just today David gave me his jacket to take to work after I underestimated the weather. He didn't have to do it (I didn't ask for him to give it to me) but he did. I really appreciated it, and I told him so via email. Later he said the email brightened his day.
Compliments ... the spoonful of sugar for life's medicine.