1. When to use 

The toggle switch should be used to toggle a setting "on" or "off".²

2. Clear Label 

When using the toggle switch within a form field, the label should be clear and concise. ¹

3. Immediate effect 

When possible, the effects of a toggle switch should take immediate effect.¹ This most closely matches user expectations because it matches the behavior of real-world switches. If this is not possible, ensure a "Save" button is displayed prominently in the UI and work with your team to explore updating to immediate effect.

4. Don't use for actions

Toggle switches should not be used to trigger one-time actions. Buttons should be used instead.⁴