For the last several years I've made network building via LinkedIn a daily habit.
I don't have to spend a lot of time on it each day, just a few minutes. But, each day, every day, I add people to my network.
Over the course of time, my network has grown tremendously. While I don't have a deep personal relationship with everyone in my list of connections I have at least had some level of communication along the way.
LinkedIn is a great tool to use when you're looking for a new job. But, I'm not looking for a job. I'm overly employed to be honest. My main purpose is to find others who are looking for new opportunities and help them realize the success they seek. True, this is my business and how I make a living but it can be just as easily applied to anyone else in the professional workforce.
Build your network even when you are not looking for a job.
Opportunities are everywhere. They are not rare. But you need to put yourself in position to have access to them. Make connections. Start conversations, even when you aren't overtly wanting something. Then, be on the lookout for opportunity.
Four leaf clovers are found by those who walk the clover fields.