Dadbelly, every word shared above is true. They describe different approaches but that's because no two kids have the same recruiting journey.
I have two outfielder sons (college classes of '21, '23) who have gone the HA D3 route (after swinging at and missing 12-6 curveballs from all the Ivys), and a 2022 pitcher who is now developing a list of schools (not as high academic). He has already written his three top choices, including sending a short video. The coaches sent back nice generic notes: "We're gonna follow you. Let us know what events you'll be at."
While generic, it's valuable when they do that because you can then follow up with them a couple weeks before an event, hopefully with new video, and prepare for a face-to-face. If there is one step that is absolutely mandatory for D3 kids, it's that they introduce themselves via email/video to coaches a couple of weeks before any camp/showcase and then follow up with coaches at the event. There will easily be over a hundred kids at any SB/HF/Stanford showcase. The sobering, even panic-inducing reality of these events is that your kid is gonna look pretty much like everyone else. Unless he is the next Bryce Harper (hopefully with a better attitude) being "discovered" at these events is a crap shoot. So, the prior contact is critical.
My oldest did Headfirst in fall of jr. year because I was afraid to wait til sr. summer to roll the dice. HF was good because he got used to the showcase format PLUS the Ivy coaches he had written flat out told him that he was one of the guys they were checking out. This was much earlier than D3's get serious and it's worth keeping in mind.
My 2019 tried the same route as 2017 but he HATED showcases. After figuring that out I got him to 5 college camps in the fall of his sr. year. He did great at four of the camps and got offers from three of those schools, plus three more offers that were kind of out of the blue. Who knows where or how they saw him.
Takeaways: contact coaches ahead of events. Create a plan that plays to your son's strengths (camps vs. showcases? a combo?). Make getting stronger and faster a bigger priority than you might think they need to be. Speed plays. Strength plays. Super cool when they play together. Pick schools that are good fits socially, academically, and athletically.
And the two biggest takeaways that I underestimated: how quickly time goes by and how little of this you, as a parent, actually have control over.
Upshot: stay grateful.