I will answer this twice since son ended up changing his commitment after a significant and unexpected change in the coaching situation. First school:
1) Travel team was invited to play in a mini-tournament on campus.
2) Summer before sophomore year, 15 years old.
3) PG/Evoshield National Underclass tournament that fall, pitching coach attended a high school game the following spring, USA Baseball National Team Championships and travel team workout on campus (where offer occurred) the following summer.
4) Travel coach arranged for the travel team tournament and workout on campus and facilitated communications with the coaches since it was before son's junior year and they could not contact him directly.
Second school, where he ultimately ended up:
1) Pitching camp on campus.
2) Winter of freshman year, 14 years old.
3) Same on-campus pitching camp the following winter, USA Baseball National Team Championships, Stanford camp, and PG Underclass All American Games that summer, MLB Scouting Bureau Underclass Invitational Game and PG National Showcase the summer after that.
4) Travel coach did not have a role.
In the end, it was really lucky for him that the school he ended up committting to just a month before signing his NLI had seen him from an early age and remained familiar with him and his progress over time.