First go to magento installation root directory1- Check npm versionnpm -v2- Check node versionnode -v3- Install Grunt CLInpm install -g grunt-cli4- Rename files - package.json.sample to package.json- Gruntfile.js.sample to Gruntfile.js- grunt-config.json.sample into grunt-config.json5- Grunt ConfigurationOpen grunt-config.json and update below code{ "themes": "dev/tools/grunt/configs/themes"}6- grunt clean7- grunt exec:<childtheme>8- grunt watch9- Now edit less css than watch will listed that file path in terminal in vs code. and refresh the page. The css changes will visible on frontend.It is very good tool for doing magento 2 development faster.