I personally believe flight strips are essential. They are the easiest way to coordinate with neighboring controllers, mostly because, if you are not using TS, Skype, or some other voice tool, typing PM's can be a pain in the butt. Just push the strip to the next controller, and you are done. Simple as that.
Also, I used to use the AutoAdd arrival and departure strips function. There turned out to be a better way to obtain strips. If you are working alone, without any other neighboring controllers, you can just hold ALT and click the aircraft and that aircraft's strip is added to your bay. When working with controllers, you can request that they push strips to you, and your bay is filled that way.