The two most effective ways I've seen to cure the common tendency to overcorrect are, (1) watching someone else overcorrect and (2) do an approach in visual conditions without the hood.
The first can be done as a safety pilot or in the back seat when another student is taking a lesson. (My CFII put in the hold and had me correct him, but I didn't find that variation particularly effective) The latter gives good biofeedback to how very small corrections done early reall smooth things out,
Yeah, I'd have to say that watching another advanced rating candidate from the back seat of the Seminole was one (of many throughout all the flying) those ah-ha moments about how much the pilot can smooth things out on instruments, and since I'm an old school steam guy, it gave me time to watch his magenta line and map more on the Garmin and see how to integrate that better into my scan when available.
I had a tendency to simply ignore it, having learned my scan over on the "six pack" and needed to widen out the field of view to take it in a bit more, but really didn't recognize that as a "problem" or how much help it could be, until I sat back there realizing what a wonderful "cheat" that is. Ha.
Up until I sat in the back, my interaction with the Garmin was more of using it as a way to dial in stuff, like an old nav/Comm and then ignore it. Haha.
Of course, prior to that even, I've shared that my DPE allowed the georeferenced plates in Foreflight too, and I only really noticed my own dang airplane cruising along on the plate on the third approach of the checkride.
It's interesting to me how much the habits built early stick with you, even if other tools on board would make your life easier. Too much time in an old Frasca back in the day...
So I still have to consciously remember to include the moving maps. One way I can suck my eyeballs into the ForeFlight screen when doing instrument stuff is to turn on their little HSI. It uses too much screen real estate for approaches on an iPad mini, but my brain is naturally drawn to the depiction of an instrument one would see in a traditional instrument cluster. So it stops my scan on the iPad for a second longer and then I think to take in the moving map information and process it.
Ultimately nothing "wrong" with just flying the six pack, but sure is a lot easier to add in a moving map and hang out in this century once in a while! LOL.
Kids and their moving maps! Nah Humbug! Tee hee. Says the guy who wonders why all the haircuts at the barbershop seem to have more white hair on the little apron (or cape, if you're more the superhero type...haha), than brown, these days.
Of course on modern simulators you can't cheat by listening for the servo motors moving the dials, either... damn LCD screen technology! You always knew you were screwing the pooch in the old ones when you heard multiple servos start to whine from the panel in front of you!