Balls, hoops, slingshots are some of the oldest known toys. Also some of the simplest. No batteries, computer skills or assembly required. But make them out of sturdy polyethylene, color them boldly, ...

Sometimes you can find training aids for your swing in the unlikeliest of items. Exhibit A: the iconic Frisbee. Hold the disc in your hands so it mimics the clubface, then get into golf posture.