I think they are talking about the Jet method, which is a way to over and under tension the mains and crosses in a specific way in order to create a more uniform stringbed. You can google it for a more specific description. I think it's taken with mixed results here, and a lot of the more highly respect regulars around here actually don't put much in store by it.
Otherwise, the only other thing I can think of is less to do with "feel of the string bed" and more to do with string accuracy. some strings you can't just pull tension once (with a drop weight) and be done with it.
Sometimes you have to pull twice, either because the string stretches a lot, or you lose tension once you remove the clamp and have to re-pull it again.
Nothing affects feel more than an inaccurate stringjob, one where you intended to string @ 50 lbs but when you measure it, it's no where close.
That just takes time and experience: string a lot of racquets, but more importantly, test your racquets afterwards. Invest in a string tension meter (you can find them at TW) and keep a string log of all your jobs.