When a close friendship fades, it's always sad and upsetting. You're left to grapple with troubling questions: Did I choose poorly? Did I do something wrong? What caused the friendship to strain? Is it too late to patch things up? Do all friendships fade sooner or later?

"Friendship is like money, easier made than kept," British novelist Samuel Butler once observed. But, though friendships are always at some risk of withering away over time or shattering unexpectedly over misunderstandings, you can take practical steps to preserve them. What follows are some suggestions for keeping friendships close.

Keeping the right balance

•Don't keep score.

Sometimes friends keep tabs on who did what in the friendship: "I brought flowers and candy to Colleen when she broke her arm, but when I was sick all I got was a card!"

Others keep track of which friend does the most calling, who does the most talking vs. listening or who is the one to initiate activities together.

Healthy friendships require giving and taking on both sides. If either friend starts keeping score-tracking who has given or received more-the friendship can start to fracture. The reverse is also true: When neither friend is keeping tabs, the friendship is likely to grow.

Just act naturally

•Be yourself.

Some people resist telling friends their deepest feelings. They're afraid to share their fears, frustrations, disappointments and negative emotions. But there comes a time in any friendship when you must open up.

You may think if you let others see your flaws they'll like you less. But they may like you more. When a friend moans about doing something embarrassing, I tell the story of how I once tripped on a fire hydrant; I was too busy waving to a friend across the street to notice what was directly in front of me, so I crashed on top of the hydrant. Not only does the story get a laugh, but it puts others at ease.

One of the best ways friends show support is by letting others know they're not alone in their mistakes. That's why it's important to let them see the imperfect you.

Don't be a control freak

•Don't try to control your friend.

Marcia's and Wendy's friendship seemed ideal in the beginning. They were so much alike: They both loved to joke, came from similar families and liked sports. They spent the summer confiding in each other, laughing and having fun.

But the start of school marked a turning point in their friendship. When Wendy got to know some new girls in her social-studies class, Marcia refused to have anything to do with them. The day Wendy got invited to a party and Marcia didn't, Marcia told Wendy what a dumb party it was going to be. Although she didn't want to admit it, Marcia was worried she was losing Wendy as a friend.

It can be tempting to want a fun person all to yourself and feel threatened when your friend spends time with others. But, if you try to dominate someone, he will only grow to dislike you. If you are afraid to let your friends out of your sight, you are probably afraid of losing them. A friendship has to be flexible enough to allow each person breathing space to explore and grow. If it is a good friendship, it will survive time spent apart.

Try new things

•Broaden your interests.

If you find a friendship drifting apart because you and your friend don't have as much in common anymore, find new interests you can share. "Molly and I became friends when we were on our high school's ski team together," says Laura. "When the season ended I made a special effort to keep the friendship alive. I convinced her to take a tennis class with me. She taught me how to do calligraphy, and we discovered that we both enjoyed miniature golf-something that had never come up while on the ski team together."

No two are exactly alike

•Learn to appreciate differences.

Jason, a high-school sophomore, says he and his best friend, Mike, rarely agree about anything. "I'm a good student, and I'm really into band," he says. "I spend a lot of time doing my homework and practicing the trumpet. Mike doesn't study much, and he thinks the band is a waste of time. I don't always like his other friends, and he doesn't always like who I like. I think the reason we've been able to stay good friends is that we've learned to accept each other's differences."

Two friends can endure major personality differences and maintain a good friendship if each has learned to respect the other person's point of view. "Genuine friendship has a lot of give and take in it," says Eugene Kennedy, Ph.D., author of On Being Friends.

He continues: "Learning how to disagree with a friend begins when you realize that it's not a matter of winning and losing; that should never be the issue. If you feel that you want to change your friend so she always agrees with you, that's not a real friendship. It's the disproportionate gratification of one person, and true friendship can never work on that basis."

Even the closest friends are individuals, Dr. Kennedy points out. You and your friend could be looking at the same thing, but in reality you each see the object differently because you are looking at it from two slightly different angles.

Always sticking close

•Stand by your friend during bad and good times.

Some people think that friendships should be judged by how well friends stand by each other in times of trouble. But it may be even more difficult to stay friends in times of joy-our friend's joy, that is. Sure, we are happy when our friends succeed and have good luck. But in our heart of hearts there may also be some envy. We may sense that, if things get too lopsided, the friendship could be in jeopardy. One 16-year-old put it this way: "I don't want to be a better basketball player than Ryan, but I'd at least like to stay in the same league."

A good way to deal with envy of another's success is to reframe that emotion. Rather than letting possible negative feelings about a friend's achievements undermine your relationship, let that achievement spur you into improving your own efforts. If he can do it, chances are you can too.

Make time for friends

•Give the gift of time as often as time allows.

Time is what we don't have nearly enough of. Yet, with a little creativity, we can make time for our friends. The key is to remember that a little is better than none and that you can do two things at once.

For example, if both you and your friend need a haircut, go to the barbershop or salon on the same afternoon so you can talk while you're waiting. If you and your friend both need to return books to the library, go together. My neighbor and her best friend take evening exercise walks together. A friend and I who live 2,000 miles apart schedule an hour-long phone conversation once a month.

It's when life gets busy that it's especially important to be open with your friend about how much the friendship means to you. If you haven't called your friend in a long time, let her know it's not that you don't care but that you've just been really busy. Tell your friend how much her friendship means to you.

Simply saying "I miss you" with a postcard, letter or phone call will help sustain that friendship during the times you're apart.