There are some applications where never seize is not recommended, check the technical manual.
Regarding spark plugs, it is easier to correctly install new plugs vs reusing old ones ( a different discussion topic). For new, tighten till hand tight and until you feel the crush washer crush. Then add a 1/4 turn.
In general though, it is good to use a torque wrench even if just to learn what different torques feel like. It is very easy to over torque small bolts. In addition if you will be doing any work like cylinder head works, head covers, etc, you have to use a torque wrench. Although I don't use a torque wrench for things lke spark plugs and t-stat housings, I do use one when installing my props, always
One brand of motor specs 40 foot pounds and the other specs 80 ft pounds. When I do the 40 ft-lbs it feels too little and when I install the 80 ft-lbs props it feels too tight!