Get out there.
One of the most important parts of making more friends is putting yourself out there. People often judge based on first impressions, if you are shy, quiet, or reserved, it is often misinterpreted as stuck up. People will be less likely to approach you and be your friend if you do not make yourself open to friends, outgoing, etc. So, get out there and let people know you are in the market for new friends.

Meet people.
It is hard to get new friends, or more friends if you never meet new people. It can take guts, but find ways to meet new people on a regular basis. When you drop your child off to school start striking up conversations with the other moms and dads around. When you are at work try venturing into another department and inviting someone to eat with you at lunch, or comment on the pictures on their desk, etc. You have to meet new people and make an effort if you are going to make new friends.

Initiate things.
Making new friends is often a scary prospect, so if you want new friends you have to be willing to initiate things and get the ball rolling. This means inviting people out, calling them, sharing your stories and hoping they reciprocate. Even if someone wants to be your friend, they may be too shy or unsure of your feelings to include or invite you. The best way to get more friends is to be the one putting yourself out there.

Work at friendships.
If you need more friends, you should not let your other friendships go in the process. It is often easier to keep a friend than to make a new one, so be sure to keep your existing friendships alive as you search out new friends. Remember that all relationships take work, but a phone call or Facebook message can go along way to keeping a friendship alive and well. So, work at your existing relationships as you build new ones.

If you want to have more friends, you have to put yourself out there. It is easier to sit back and do nothing, but if you want friends, you have to make an effort. Invite people to do things, and work to build relationships with people. Make sure people know that you are open to making friends. The worst thing that can happen is that you will not make a friend, and since you already want more, the risk is worth the potential reward.