Practice makes perfect. If you are working on something where you have time simply mess around with your wrenches, ratchets, and air tools while following with the torque wrench. It really helps give an idea of what amount of force does what.
After a while you can tell what your impact is doing by sound, and feel. Same goes for wrenches, and ratchets. You can feel it tightening. You can even feel the bolt stretching! The worst part is adjusting your force based on the leverage of the tool. Well, that and if you are messing with stuff like aluminum, or stainless. Yuck.
Unless we hit a time warp, it isn't possible for me to have anywhere near 30 years experience.
Oh, after you figure it out you can start betting people you can tighten something within a certain range! Easy money!