My son started his recruiting journey after playing varsity his freshman year. We had a list of close to 200 coaches and email addresses. We worked together on a form email that he and I collaborated on personalizing to each of those coaches. He included a link to a small web site with recommendations from coaches and teachers, GPA and academic info, if anyone wanted it, and a link to his video which was available on You Tube.
Whenever he heard from a coach — even a camp invite — he responded, asking questions or offering more details. In most cases, he heard nothing back (among other things, he was too young for them to email, which we knew, but thought he might get on their radar).
Throughout high school, he went to a showcase before each season began and when it ended to measure his improvement, and we shot new video and then he would send another email to the list of coaches he had heard from (even those that just responded with camp invites), with links to the updated web site and the updated video.
He was very persistent with this, and his skills improved. He picked up offers from I think four D1s, a few D2s and several JUCOs. He talked to several D3s who all said "look, we know you're not coming here, but if things don't work out wherever you go, we're here." He still has good relationships and visits with some of those coaches from time to time.
He is now at a P5 that didn't respond to his first email, then invited him to a camp, then sent their RC, PC and HC to games to see him in action, and finally offered him early in his senior year.
Obviously, baseball skill matters, but so does just working hard and not closing any doors until absolutely necessary.