How do I use Appium Inspector to find mobile locators?

Flow: 1) install Appium Inspector desktop app, 2) start appium server (appium --base-path=/wd/hub), 3) in Inspector fill capabilities (platformName, deviceName, app or appPackage), 4) Start Session. You get a live screenshot + XML source tree — click an element to see its id / accessibility id / xpath. Prefer accessibility id and resource-id over xpath in your test code.