The best bang for buck is to go to ShowBall or Headfirst; tons of HAD3 coaches at both. ShowBall typically has the HCoach attend. The individual camps are early fall and full of hopeful players. Very few recruited players come out of those late camps. The Ivy camps are an exception; HAD3 coaches help to run the Ivy camps. Great place to be seen by the Ivy, and likes of GTown, Holy Cross, NESCACS, JHopkins etc.
As 2024's the HC's will look at emails this spring. While your son's are preparing for HS spring season, start playing around with video for pitching, fielding, hitting. It takes a while to get it refined.
In that email ask the HC specifically which showcases, camps or tourney's they'll be at. You can work your schedule around that. Your goal should be to find a way to be seen by them at least twice. My son is at a NESCAC and he attended 2 ShowBall and 1 HeadFirst, and was fortunate to be seen by a few of the coaches at a few tournaments.
The HC's are just starting to work with the roster prepping for a March 3-5 start (at least ours is). While the HC's are traveling they have the time to scan for emails and look at video.
Colleges like Amherst, JHopkins need a minimum of a 32 ACT to be supported by Coach for admissions. Coach has to love your skill, then he needs the 32. Most other NESCACs & similar HAD3's need a min 30-31, few need a 27-28.... This is a ball park from where it was 5 years ago. So, your baseball skills have to be really needed, plus you need to know HC will have no issue supporting you thru admissions if liked.
Additionally, you'd be really surprised how good the players are. A number of them were already being looked at by mid D1's in their area. But the players were looking toward higher academic schools and thinking of the next 40 years vs 4. Also, most were vying for Ivy's and had respectable skills to be considered, but they just missed the mark, or preferred a smaller cache high academic school experience.
Plenty of threads on this site talking to this topic. Feel free to DM with any specific questions. Good Luck
Edit: the guideline for ACT for HAD3 was the 25th percentile number. It was 31 for son's school 5 years ago, just noticed it's now 32.....Kids are getting smarter and getting better at taking these exams. Damn...Ask the HC