OK, so maybe I'll start - anyone else going to add?
A fundamental problem for me is increased wage inequality - its all very well trying to deal with poverty & income inequality through redistribution and the benefits system, but it's expensive, difficult to achieve without messing up work incentives etc, and also very vulnerable (as we are seeing now) to anything from cuts through to full scale dismantling when right wing parties are in power. Whereas, if you can reduce wage inequality, you reduce the need for redistribution, and hopefully have a more long lasting impact on society.
At the same time I would like a massive move towards economic democracy, to sit alongside our parliamentary democracy. I hate the word 'empowerment', but it kind of expresses what I mean, unfortunately - ordinary people having some real control over their working lives. I guess that's going back to the roots of the Labour movement, and thinking about who controls the means of production. I definitely wouldn't want to see re-nationalisation in the form of monolithic State enterprises - IMO that didn't lead to any real workplace democracy any more than State socialism led to democracy in the eastern bloc.
I guess if I were setting policy, I would be trying to massively encourage worker owned businesses in whatever form with financial incentives. So, for example, lower rates of employer NI for businesses that are more than 50% worker controlled (not necessarily directly worker managed), NI or corporation tax holidays for new worker controlled businesses, and practical / legal support for businesses looking to become worker controlled.
My other main policy strand would be to try as far as possible to reduce taxation on 'good' things like employment, and increase taxation on environmentally destructive activities. So, maybe I would pay for my reduced NI rates (or perhaps for my improved public transport, moving away from the economy) by increasing fuel tax, for example.