With LinkedIn, there are only two things you need to be doing right now:
i) Adding connections, and
ii) Getting recommendations
You need to be doing these things on an ongoing basis because people’s willingness to connect/recommend you decreases the longer they haven’t spoken to you.
You need these things in the first place because recommendations/connections are a great way for people to find you, the more of them you have the more important you seem, and connecting with people enables you to better understand your own network, and thus tap it for whatever reason you need.
So if you’re not a big LinkedIn user, here’s what I recommend:
1) Try importing from your address book/faceboook etc… there might be people who are on LinkedIn whom you know, but have not connected yet.
2) Make sure when you meet someone who might be useful, you try to connect with them on LinkedIn. If you manage to make the connection, you are giving yourself a platform to deepen that relationship at a later date, if you so desire. This is made easier by having a smartphone with LinkedIn installed, and adding them in “deadtime” when you might be travelling or waiting for something.
3) Try asking for recommendations from former/current employers/colleagues. If you offer to reciprocate, the likelihood that they’ll accept will be greater.