In the high school days of class schedules and school dances, friendships were easier to maintain. Sure, there were ups and downs and teenage dramas, but unless your friends moved away, you largely moved in the same circles. As an adult, a busy life can make it hard to both stay in touch with old friends and find ways to meet new ones.

There are many reasons friends lose touch: relocating for school or work, getting married, becoming parents, working long hours, or simply not having time to keep up with it all. The same difficulties that make it hard to take time for your old friends, can keep you from making new friends as well. Remember, just like romantic relationships, friendships need some work to keep them going.

Whether you're looking to make new friends or keep up with an old one, think about the following 5 tips for fostering friendships:

1. Make time for your friends — In the same way “date night” keeps a marriage fresh, friendships need their own social outings. If you don't have time for a full-blown evening out, still try to get together for a drink after work or a latte on a weekend morning. See if a friend wants to join you for a walk or a shopping trip. While it may not always be easy to get together in person, make time for regular phone calls and for emails that are more than forwarded jokes.

2. Don't rely on social networking sites — Facebook is a great way to stay up to date with friends and family alike, but it can also give you a false sense of a social life. Trading status updates, commenting on each others photos, or visiting each others' virtual farms is entertaining, but not the sole basis for a friendship. In addition to your virtual contact, take time to visit with local friends in person, and call long distance friends on the phone.

3. Take a class or join a social group — If you're looking to make friends, taking a class or joining a social club is a great way to find others who share the same interests. To maintain your current friendships, take a class or join a club together. Dance lessons, yoga classes, book clubs, photography groups, and cooking classes are just some of the ways you can spend time meeting new people and building up your existing friendships.

4. Pay attention to friends' big events — You have a lot going on in your life, so do your friends. Remembering birthdays is one way to show you care, but paying attention to the small milestones may mean even more. Has your friend mentioned an important meeting at work? Has a friend who's gone back to school been studying for mid-term exams? Make a note when your friend mentions an important event in her life and take a moment to check in to see how it went.

5. Keep the plans you make — Things come up, and plans sometimes change. It's one thing to be adaptable; it's another to be known as a flake. Part of being a good friend is being reliable. No matter how understanding they may be, no one likes to be stood up or have their plans changed at the last moment. When you make plans with a friend, make every effort to keep them. If you're tired and just don't feel like going out, give yourself a push. You'll often be glad that you did.