Social Trust is extremely important for any given economy. It's level will determine how much overhead the economy needs to function normally. In low trust environments, the same service or product will cost twice as much to account for all the trust checks that aren't needed in a high trust environment. So everyone would probably agrees that more trust is better.

But, here's the catch, trust is more easily broken than it is built. Meaning that if you have 9 trustworthy persons and 1 untrustworthy person, it brings down the whole level of trust because people could expect the other nine no to be trusted. It probably gets even worse if you have 5 or more untrustworthy people as lack of trust becomes the normal way of conducting business like it can be in North Africa for example.

Like the article about Denmark accurately reported, a high level of trust doesn't have a single cause, and some factors can't be emulated easily if any (historic factors, homogeneous population, specific culture, country scale). What's worse is that a good economic situation will encourage trust while a bleak economic situation will do the opposite. So it is a self-affecting factor as social trust improves economic efficiency.

I do have ideas to improve social trust, and they mostly start at the top. Most politicians thrive on dividing the public by riling up the ones they are hoping a vote/campaign contribution from against the ones they know will never vote for them. So a change in their public discourse would improve the social trust. I'm not that hopeful for any change in that regard, because the current administration is actively hitting at social trust on all sides. What's worse is that they are riding off improving economic outcomes probably still caused by Obama-era policies, so there will be no immediate feedback for their actions until they aren't in office anymore and beyond that.