Establishing laws, enforcing contracts, defending the country, and interfering in as few ways as possible? I need some more specific, in-depth and well-detailed explanations and reasons.
Establish a solid legal system. Have non-corrupt police and courts. Enact laws so everyone understands what’s legal and illegal. Avoid the temptation to go outside the law.
Establish a solid public education system. Have schools that all your country’s children can attend. Teach a secular non-partisan curriculum - your purpose should be education not indoctrination.
Rigorous enforcement of property rights.
If your physical assets (home, car, land, etc.) can be stripped from you with impunity by others, you aren’t likely to make much effort to improve or maintain them. Why bother painting your house if you can be run out of it next week?
Same goes for intellectual property: strong protection of patents, copyrights, and trademarks makes it possible for creative people to profit from their own ideas, and the rest of us live better because of it.
First: make it clear that any official caught taking a bribe will be prosecuted and fired. Then make sure the laws are clear and enforced. Don’t make any law you are not prepared to fully enforce. Make no laws against victimless crimes. No prostitution or drug laws. Laws against impaired driving are fine. And make sure that everyone is a stakeholder. Many decades ago, long before current preoccupations, I concluded that the main economic difference between north and south America was the fact that in the latter, a few robber barons came in and ended up owning everything, while in the US, everyone had a decent chance at least of getting into the middle class. This the conclusion I drew maybe 40 years ago while the wealthy paid high taxes and a hundred thousand was enough for a company president (I hadn’t ever heard of a CEO at that point).
Protect the weak from the strong. That pretty much covers all the above points, and a few more.
Separation of church and state. Civilian control of the military. Protection of freedom of assembly and freedom of speech. Rules or laws in place to prevent leaders from staying in power for life. Establish and maintain a professional level of standards for anyone in the law enforcement or judicial system, and pay them well. Freedom of the press, especially in regards to critiques of government or politicians. Government should have checks and balances.