Looking back, I think Yoda just wasn't prepared in giving a crash course on Force use. He spent his career in the Jedi temple. It was a monastic order where initiates were expected to spend their time pondering the Force. In that setting, it makes sense to give a few snippets of wisdom and leave the student to work it out. A student gets a lot more out of taking a week to progress on his own than in having the master spell everything out. Yoda's goal was to give them the tools they'd need to eventually become Jedi Masters. This method may be less than ideal for rapidly getting a neophyte in shape to go fight the Empire, but that doesn't make it bad in general.