As my son is entering his junior year I am of the opinion that showcases and travel ball that targets showcases are a good avenue to get noticed by college scouts. My son attended a Complete Showcase in Houston a few months ago and there were 39 college coaches from D1 to NAIA.
Another avenue is to make small clips of a player batting, pitching, catching, hitting and email college coaches directly. This is the cheapest way to go obviously. I know a local kid that was recruited to a large D1 as a pitcher and played nothing but American legion. I'm sure his 90 mph fastball had something to do with it.