There are a few things I'd like to recommend to you if you're not sure what the future holds, but you want to be ready for whatever comes along:
Update your CV when you don't need to
Those quiet times when you're comfortable in a job are the perfect time to update your CV. I used to update mine with tired eyes usually on the evening that a job application needed to be submitted. Now I force myself to update it when I'm settled in somewhere.
This works well for me for a couple of reasons. Firstly, it's a great way of taking stock of where you are and how you are developing professionally. Second, it can save you a lot of pressure if a job comes up at short notice. Finally, you can match it against opportunities when they come up more easily. I just find it so much easier to see a picture of what my experience looks like when it's written down.
Write down your publications, presentations and events attended
I've never included these on my CV before so I'm sure I can't be the only one who fails at this routinely. Recently I decided to collate them, and it was much harder to do now than if I'd kept track at the time! It amazed me to see it all written down together. It seems so strange now that I'd never done this before.
Remember that it's a small sector really and people you meet now often turn up in unexpected places:I'm pretty bad with remembering names. Anything that helps me here is welcome, and I do use LinkedIn to help me keep touch with people. One thing I've just done is to turn on the feature on that lets people see if you look at their profile. It should allow me to learn more about the clicks that my profile gets, but I also decided that if I wanted to look at other people's profiles then there's no reason why I should hide it. I guess if you're a stalker then this advice won't be for you, but otherwise I think there is nothing to lose. Also, in terms of building a professional profile I don't mind if my name pops up occasionally on there.
I can't tell you how often people I've met at conferences, tweeted, read and listened to that have ended up working with me, interviewing me (or interviewed by me), or just reappeared somewhere in my professional life.
These are fairly small scale, common-sense suggestions I think, but doing these things has helped me feel just a little bit more in control when your career will have a life all of its own.