Rejoining the EU would be a good start.
As would abandoning all pretensions of "greatness". We need to accept that we are a small nation with little power in the global arena.
A more proactive approach to climate change and significant investment in the green economy/green jobs.
Much more investment in education, and a heavy focus on addressing social inequalities in the early years. I fundamentally disagree with your approach to education, OP, and think that the arts and humanities should be taught to all, it's the mark of a civilised society. However, I don't disagree with the proposal to invest more into the teaching of practical life skills as well.
A series of proactive, evidence-based policies to address the massive inequalities that persist in our society, whether related to sex, race, disability, sexuality or social class.
Proper investment in health and social care. A more proactive public health strategy which focuses on actively promoting good mental and physical health, and prevention rather than cure. And a less xenophobic immigration policy that recognises the huge contributions that immigrant labour makes to these sectors.
Significant investment in local communities and projects that reduce social isolation and marginalisation.
Financial incentives for companies that promote employee wellbeing and work-life balance effectively.
Higher taxes to pay for all of the above.
And a culture which genuinely values diversity, promotes respect for others and encourage hard work and aspiration.