After your viva, before you are finished with your PhD completely, take a little time.
Thank everyone you need to thank.
Reflect on what you’ve learned over the years.
Decide on what you don’t need to take with you into the future – the number of papers and notes I’ve kept for fourteen years without needing them is astounding!
Find someone who needs help or advice and offer what you can.
Then when you’re ready, move on to the next big thing.
Whatever it is, as important as your PhD and viva were, I’m sure that what you do next will be even better.