Summarize this article in one sentence.
There are a lot of reasons why people lose friendships, from distance and time to conflicting schedules or changing interests. You need to spend some time examining what caused you to drift apart so that you can find ways to remedy the issue. If, for example, one of you moved across the country, you may not be able to become best friends again easily. But you can still have a meaningful friendship using email, Skype, and phone calls. Don't feel like you need to catch up with each other instantly. Take the time to send a quick message to your friend with your contact info and tell them you would love to talk sometime. Don't feel like you need to fill them in on your life now — save this conversation for when you meet later. If you live far away and cannot meet anytime soon, spend some time with each other online or on the phone. The best way to build or rebuild a friendship is to talk. You don't have to get into all of your secrets, but giving a quick update on your life makes your friend more likely to share things about him or herself. Friendships rely on trust, and you need to let them know that they can still trust you with information and details about their life. The best way to do this is to show that you still trust them with your own stories. Move beyond surface conversation to talk about things that matter to you, like your life and work. Friends usually talk about much more than the weather. Think of an activity you both enjoy doing together, and arrange to meet up. A light, casual, one-on-one meeting is the best chance to get to know each other again and rekindle the friendship without pressure to be "besties" immediately. Try to limit this first meeting to 1-2 hours — the goal is simply to reconnect with each other. Don't try to rush right back into "best-friends" territory. Have realistic expectations for this first conversation, especially if the last time you talked was 8 months ago or if you ended on bad terms. Have a friendly, open tone as you ask what they've been doing and how they've been. If things go well, you can begin to get into deeper, more involved conversations. Relationships—romantic or otherwise—take time and energy to maintain. If you reach out and reconnect, then quickly disappear off the face of the earth again, chances are you won't be able to rekindle your friendship. Schedule times to meet or talk, ask how they are doing, and find ways to include them in your life to truly reconnect.  Meet for drinks once a week. Invite them to parties or events with "new" friends. Send letters or emails with details from your life from time to time.

Summary:
Think about why you drifted apart. Make contact with a brief note or call. Talk on the phone or exchange emails to restart conversation. Open up about your life first. Set up a time to meet in person. Start slowly. Continue making time for your old friends.