I agree with All of the replies.
I found that players respond well when they hear what other players have done or would have done better, if given another chance.
I connect HS Seniors with local Collegiate League Teams, since most can carry at least 1 HS Graduate that is committed to attend College that year.
Even though the playing time is scant, the experience of riding the bench or the bull pen with college players in a less restrictive environment provides the BEST knowledge of what's expected .
In addition to the prep experience, there's no better way to see college pitching.
I recommend incoming Freshman DO NOT play summer baseball with their piers. Even the bat boy learns from being with the boys!