NICs need merging into Income Tax. That will close a few loopholes and ensure that those over the state pension age who earn more than the Personal Allowance will pay the same taxes as the rest of us.
Roll the Winter Fuel Allowance into the basic state pension. At least then it will be taxable for those earning over the limit and we won't have to have the arguments about means testing it.
End the triple lock. specifically the bit about it increasing even when wage growth and inflation rates are low.
State Pension Age to 70. Sorry, but we'd be lucky if it didn't end up higher, demongraphic changes are not in our favour.
Inheritance Tax is too easy to dodge. Instead of IHT, charge CGT on assets when they are liquidated, backdated to the last sale of the asset. This could be quite lucrative for inherited properties in London. Dividends and CGT need taxing as any other income is.
Phase out child benefit for new claimants. It was introduced as an alternative to the minimum wage, but we have the highest minimum wage in Europe now. The marginal tax rate when it is withdrawn for higher earners harms productivity. At the same time, kids should be accounted for in the tax system like the French do - if you have kids in France then you can share their tax thresholds (which are half of an adult's) which takes a bit of the sting out of the cost of raising the next generation.
Restore the personal allowance for high earners. It's another marginal tax rate cliff edge that is damaging productivity.
Build more medium-rise development. Sprawling suburbia is expensive to run public services to. This is more efficient, without being the tower blocks people hate. Council Tax reform is long overdue, the valuations are arbitary and outdated. Instead the property's footprint should be used - it's something you can measure properly and again sprawling properties cost more to serve. Agricultural land, woodland and nature reserves exempted of course.
Non-resident parents must pay towards their offspring's upkeep, regardless of their declared earnings. No more dividing the same amount between ten kids from several different mothers as you'd have had to pay for one, the costs of bringing them up don't drop. A kid costs X amount to bring up, therefore you must pay Y. No use working cash-in-hand or sitting on the dole to avoid your obligations, you still owe it - and expect some sanctions if you don't pay.
Social care funding cannot remain the responsibility of local councils. The money needs to be found by central government. Even if the politically courageous solution of selling the patient's assets to fund it is required.