From my experience, if you do enough work, they will find you .
Just make sure you don't screw yourselves money wise, always be fare, and make a case for what your charging as you are aware, most people don't understand what you do on a daily basis.
Word of mouth will bring you all the work you want, but a good portfolio will bring you to the top of the pile.
If your working on NDA, charge more, and they will pass your name on.
If they don't they are being greedy.
Phil