I think we are close to 'holding all things in common' when we realise that we own nothing, and are simply stewards of God's assets.
When someone requires something, we happen to have what they need (food, clothing, money), and just hand it to them without seeing anything difficult or unusual in that gift. When we consider the assets of the church as a whole, and seek to minimise everybody's expenses, even if that means bearing a disproportionate portion ourselves.
When we can look at our van (for example) and think "God's van" not "my van". Then, when a brother needs transportation more than we do, we are happy to lend or even give it him. With no emotonal attachment to it at all, no feeling of loss, because we lost nothing, just passed God's asset to the next steward. We still have private property, in that we are fully responsible for the property we 'own' and must care for it as our own, and not throw it away for no reason. We will give an account to our Lord for our management of His assets. But we are happy to pass assets to another steward when it is truly right, because all assets are held in common by God.
It's a mindset that we may never fully achieve but is worth striving for.