There are a couple of events that fire quite regulalry and have awesome effects, so it's good strategy to create the right circumstances for them to fire.
The best event I think is Prospering Times. Essentially, if you have Patron of the Arts, an Artist advisor, 500 ducats in cash and at least 25 cities, you get a university or Fine Arts academy every 20 years that only cost 500 ducats. (with high Innovative & stability you can bring this down to about 12 years)
It's the best investment in the game, with a RoI of only 8.3 years! No magistrates and even better, these manufactories do not become more expensive with how many you have build! This event makes PotA one of the best NIs out there.
Other events that are awesome are the three reform events. These fire every 30 years, require a specific National Idea and some other requirements and they move sliders for you. With these three events, you never need to touch Innovative/Narrowminded or Quality/Quantity. Here are they:
Architectural Development. Gives +2 Innovative. You need Patron of the Arts and a monarch with ADM >= 5. Very useful for most countries, extremely useful for those who want to Westernise quickly.
Military Development. Gives +2 Quality: You need to have the Grand Armee NI and your monarch is a military leader to make it fire. You can also use it to move +1 Quantity, if you prefer Quantify.
Social Reforms. Gives +2 Free Subjects. You need to have Humanist Tolerance for this to fire. However, this event will only fire if your Serfdom/Free Subjects slider is lower than -1, so it will only bring the slider up to the middle. Still, can help with going from extreme Serfdom to neutral. Also, as with the other reforms, you can move 1 toward the other side, if somehow you want to have more Serfdom.
If you know any other great events (f.e. other reliable events for moving sliders), please share them with us!