Be cautious when someone tells you there’s only one way to get ready for the viva.
I think there are some really good principles in effective preparation. Read your thesis, annotate it, find opportunities to practise, and so on – but there are many ways you could do all of those things.
Some people will want a mock viva (and some candidates will feel they need one), while others will prefer simply talking with friends. I think it’s better for candidates to take their time to read their thesis, but because of preferences or other priorities that won’t be an option for some people.
Ask others about their experiences, ask for advice, but think twice when someone says, “Do it my way.” It will probably be well-intentioned, but it might not work for you. Think about how it fits your thesis, your preferences and the options you have at that time.
And be generous with your advice when sharing it, but understanding to know that what worked for you might not be appropriate for your friend.