High school teams tend to be as good as the rec leagues that feed them; and, some of the most successful high school coaches I've known over the years have put a great deal of effort into assisting and supporting the rec leagues that send players up to them. Most have done so as a long-term effort; helping them make incremental improvements over time that steadily improved the quality of player they produced.
The coaches do so in a variety of ways; but, it begins in establishing a close relationship with the rec league officials who are directly responsible for baseball at each local league. If you're not currently involved with them, I'd recommend that you sit down with them and make an assessment of what each needs. Chances are, there will be elements of their program that you'll be able to help them improve.
The better they are, the better your team becomes. Dedicated effort on this front will pay you long-term dividends. I've seen it in a number of cases.