The only things for which I use a torque wrench on a bike are Sturmey-Archer axle nuts. These are made of a soft white metal, and designed to strip before the more expensive (and hard to replace) axle. I only use 20Nm on them.
On a car I use a torque wrench (two different ones, actually) for spark plugs (it's v.easy to strip cylinder heads) and wheel nuts (mainly to ensure even pressure on the brake disc).
I can't remember the last time I stripped a bolt or had anything come undone on the road. Years of working with BSOs gives you a feel for when a thread is tight enough, and what different materials will take.
The bolts on stems work pretty well with the "finger tight using the wrong end (less leverage) of the allen key, then half a turn" method.