Yeah, practice practice practice. Throwing long courses helps too, because it'll force you to add distance.
I also committed to the right pec drill and philosophy a while back, and my accurate golf distance is now around 375'...still improving fast (I can feel the potential for a lot more to come). The increase in accuracy at 350' is really stunning for me, and is one of the most important things I've gleaned from the right pec drill...part of this is that I'm not using much effort to make the throw, I've stopped trying to muscle the disc along, and it makes an enormous difference. I previously (like 6 months ago) used to be able to reach 300'+ distances, but often with a ton of scatter (large error ellipse). Now I'm usually in scoring position on almost every hole I play at courses with holes in the 300'-400' range. I'm also driving an awful lot with my putter (Pro Challenger), and I only pick up my high speed drivers for shots in the 350'+ range. If I can improve my putting some more, I'll be a relatively competitive player by California standards.