As for applying proper torque values to fasteners, I, like many others, usually go by feel. The purpose of a bolt is to mate two surfaces together without fear of them coming loose during service. And this is done by actually threading the fastener in until it hits a "soft" stop. And here is where I go into "by feel" mode. I find that I can generally go from 1/4 to 1/2 a turn in order to seat the fastener.
If I haven't a particular re-build before, I usually proceed with extreme caution and back out 2-3 times and do it over, just so I can get a feel for this particular fastener. In over 45 years of wridin' and mechanicken , and with a fair dose of plain ol' good luck, I've fortunately stripped only a small handful of bolts - Hallelujah!!
The bolt will acually "stretch" just a bit, this is how it maintains its fastening power. And you can feel it if you sit back and really concentrate. Maybe find some junk surfaces that could be used as beta sites and stretch away. A little bit of practice here will pay off big in the future!
-CD-