Tim Ferris in [4-Hour Chef](http://fourhourchef.com/) quotes Chef Jeffrey Zurofsky:

> "make sure you roll them out by hand first. You'll get twice as much juice."

This should work regardless of the device used to aid with the juicing.  I'm personally not a fan of the crushing devices as they tend to break the seeds which release bitterness.  The rotating citrus juicers (electric or otherwise) such as this one work for me:

![enter image description here][1]


  [1]: https://i.sstatic.net/alGSg.png