Make the dial indicator plunger as close to parallel with the jig base as possible.
More info article: http://www.garagewoodworks.com/Align_90.php
My website:
http://www.garagewoodworks.com/
Plans for sale:
http://www.garagewoodworks.com/GW_Store.php
Buy GarageWoodworks Stuff:
http://www.cafepress.com/garagewoodworks
Follow on Twitter:
https://twitter.com/GarageWoodworks