I have always thought that the difference between an experienced good mechanic and an average one is the ability to sense and feel torque/bearing play/etc. I see a lot of bike mechanics who really have a hard time knowing just how loose or tight a bearing is unless they ask someone. I also see a lot of bike/car mechanics who just don't get "it" when they are tightening down a fastener that they need to slow down or stop. They don't understand the difference in feel between a nearly fully tight fastener and a still too loose fastener. Same with tightening nipples on a wheel. I have noticed that I can feel the differing tension building in just how the nipple feels as i tighten it. A lot of people who are newbies at building wheels (like me!!) fall into two camps, the people that understand how torque/tension feels and the ones that don't and have to purely rely on tools like tension meters to judge their wheel builds.

The feel of torque and tension is a very learned behavior.