Building connections is essential for making LinkedIn work for you. It's not just about what you know but who you know. Your connections are the people you know directly. They're the ones who either you've invited into your network or who have invited you. Either way, they don’t become an official connection until the invitations are accepted. Your overall network includes your 1st, 2nd and 3rd degree connections.
How to Get in Touch
There are three ways to get in touch with people:
Invitations – You can invite anyone whose email address you know.
Introductions – These can be sent through a direct connection of yours to anyone in your network. The connection receives the request for an introduction and they can choose to forward it or not.
InMail – This is LinkedIn's internal email system and you have to pay for your InMails. Premium memberships come with a set number per month. However, you can use them to contact anyone with a LinkedIn profile.
When you contact anyone through LinkedIn, it's essential that you make it as personal as possible. The site provides a canned message but it sounds terse and impersonal. It's much better to take a few minutes and create your own message. In your message, remind the person who you are. Even if you're sure they remember you, give them a point of reference. Mention the project you worked on together or whatever way you have a connection with them.
Searching for Connections
There are several ways you can search for connections. One is to simply upload your email address book and let LinkedIn send out requests automatically. This is convenient and saves lots of time, but it's much better to send out personalized messages. You'll have a much better chance of them accepting your request. You also get penalized if someone clicks on the box that says they don't know you.
Another way to find people you know is by looking at people in your network. Look at who your connections know and see if there's anyone who might know you.
Let Them Come to You
If you're active on LinkedIn, people will find you. Make sure that your privacy settings allow them to. Participate in groups, update with fresh content often, use LinkedIn Answers and become an overall hyperactive user. Groups are especially good for growing your network because you have a chance to communicate directly with so many like-minded people. If you do this, people will find you and your network will grow naturally.