"I'm working on my approaches for an instrument rating, but I keep overcorrecting on final approach. Is there an easy way to fix this?" - Anthony W.
"The simplest tool is probably a heading bug. Get centered on the inbound course and then set your heading bug to match. Most heading bugs are 10 degrees wide, or five degrees left or right of your current heading. If you drift off course to the left, turn right to the edge of the heading bug and no more. This is exactly five degrees of correction. If that's not enough to close back on course, turn the heading bug to center on your current heading, and then turn five degrees further, which is the new edge of the heading bug.
Quite quickly, you'll have a heading that keeps you on course and turn limits of five degrees left or right to fix any errors as you fly. Correct no more than five degrees at a time. You can even dial that down to two or three degrees in the last stages of the approach.
If you use GPS track to stay on course, use the same five-degree limit: Your track should never be more than five degrees left or right of the desired course.
This technique becomes almost unconscious. I flew a Sandel digital HSI recently and was zig-zagging down the approach course like a drunken sailor. Then I realized the Sandel heading bug was 20 degrees wide and I was overcorrecting. Using half the Sandel heading bug—the five degrees I wanted—worked perfectly."