It might start with a real analysis of why people did vote to leave, what the concerns were and is there a way to address those concerns without leaving? (I don't think there is, but we can but try!)
I think that the concerns expressed by many people are not necessarily the real cause of their discontent. My own view is that there has been chronic under-investment in many communities that have failed to keep pace in a globalised world. The old industries have gone and we have not considered how to replace them. Our education has been inadequate to prepare people for living in the modern world. This has left many of our young people with a lack of direction and little hope for a better future. We have failed to invest properly in affordable housing. We have failed to invest properly in the NHS and to plan for a world in which people are living much longer. We have failed to invest in the social care system. We have failed to invest in the infrastructure that might tempt companies away from London and the South East. And yes, we have failed to listen, over a period of several decades, to the people telling us that the system wasn't working for them.
In that climate, it was easy for the right-wing media and politicians like Farage to peddle the argument that the difficulties faced by people in so many parts of the country were because of the immigrants coming in, but that argument simply doesn't stand up. Yes, the immigrants will put some additional pressure on our health care system, but the majority of them are young, fit and healthy, and more to the point, our NHS would grind to a halt without them. Yes, some immigrants have taken unskilled jobs that could otherwise have been taken by local workers, but overall, immigrants put money back into our economy and that helps to create more jobs overall; the real problem that we have with unskilled jobs is that it's much cheaper for many companies to outsource them overseas, and that isn't going to change when we leave the EU.
My biggest objection to Brexit is that it isn't going to solve any of the problems that led people to vote for it, it's going to make those problems worse. And I think the tossers who headed up the leave campaign have known that all along, and they don't give a shiny shit about it.