Question: With reference to ‘plant[ing] many virtuous roots’ in Vow #20 of Amitabha Buddha and ‘cultivat[ing] much meritorious virtues’ in Vow #19, how should one do so?
Answer: ‘Virtuous roots’ are what give rise to ‘meritorious virtues’ (that are also known as ‘merits’). The easiest way to create them is by Nianfo (practice of sincere mindfulness of the name of Amitabha Buddha – ‘Amituofo’), as can be seen at https://purelanders.com/2017/11/11/does-nianfo-accumulate-merits
When Nianfo is done sincerely, it also spurs us to create more merits via the Six Perfections in everyday life beyond Nianfo sessions, as can be seen at https://purelanders.com/2016/01/05/how-is-mindfulness-of-buddha-practice-of-the-six-perfections (More ways will be explained in the Project Lotus course in detail.)