Meeting people and making friends in your teens probably came easy. After all, you were most likely in school and around the same age group. As you reach your 20's, new friendships seem to come to a dramatic halt. The people you work with now span all ages and interests. However, you can still make new friends by looking in places you may have not previously considered.
Be open to striking up conversations wherever you go. For example, if you're at the Laundromat and you see someone in your favorite team's jersey or shirt, make conversation about the team. If you're browsing the library or bookstore shelves near someone else, ask for their recommendations.
Attend a church, synagogue, or other religious or spiritual meeting place of your choice. You'll meet people with similar views and values. As you socialize with new people each week, you'll have the chance to develop a friendly relationship with some of them.
Join a club. If you have a hobby that's club-represented in your neighborhood, join it. You'll already have at least one thing in common with the other people in the club, which means breaking the ice won't be as difficult.
Volunteer in your community. Your neighborhood probably holds various events throughout the year, and volunteering is a good way to meet a wide range people. You may meet someone with similar interests.
Tour the gathering spots in your town: restaurants, clubs, sporting events. Conversation inside social places is often easier to initiate, since everyone is usually relaxed and friendly.