How to properly use the belt tensioner bolt when changing belts on a civic?

I found this great answer, the second one: http://www.justanswer.com/honda/1k3fw-change-alternator-belt-2003-honda-civic.html

On part (7) and (8) it says to turn the belt adjusting bolt counter-clockwise to loosen the belt. But how do I gauge the bolt and belt tension after I put the new belts on? How do I know when I've screwed the bolt enough, too much or too little?

With nearly all cars You use a torque wrench on the tensioner there's usually a 1/2inch square drive hole in the flange and tighten the bolt while holding the torque. You need one of those needle scale wrenches not the click stop ones.