Practice is a big part of it. Don't be disappointed if you're time is a little higher than other i-clubbers and it's your first time. It's just a matter of being familiar with the whole process and learning the best way to launch. I found it helpful on one of the better runs I did to play make believe and pretend the the 12 second 'vette in the lane to the left of me didn't exist.
When I went for the first time ever not too long ago, I pulled a 13.6 with a 2 flat 60 ft time as my best run with half a tank of gas and Vishnu Stage 0. Some of the runs before that were just too embarassing to post, and would show how much of a newb dragger I am. Basically I sucked, and will know what to do better next time.
I'm gonna try the method prescribed by AZScoobie and see if I can shave .2 off that 60 ft time and hopefully pull a 13.4. If it kills the clutch quicker then o well... I guess it will be time for a lightened flywheel to go in while things are apart in my driveway.
Also, I seemed to do best when I spent as little time in 4th gear as possible (shift near redline in 1 - 3). 4th gear kind of blows, and might as well be overdrive #2 in the WRX. If 4th gear was a woman if would be Oprah Winfrey.