The other strategy is to have NPCs do things that the PCs have to respond to. The most obvious is for NPCs to attack the PCs, but it could be more subtle, such as a city council increasing taxation when passing through the city gates, or an arch-mage casting some sort of aura-spell that accidentally (or deliberately) affects all spell-casters in the kingdom, or whatever. The point is that if NPCs do things that direct affect/annoy the PCs then the players will eventually organise themselves to investigate, without needing a quest handed out to them.
This is the main one I try and use, in preference to the PC-Game style, "talk to NPC, get Quest". When we say NPC, it could be people, organisations, monsters, or whatever - the key point being there's one or more sources of Conflict, which the PC's i.e. Players feel motivated to do Something about, without someone having to explicitly spell it out as a Quest.
I'm running SKT, which is full of stupid "quests", but I choose to run it differently... For example, if Giants are trashing the local villages, what do the PC's do about it? Do they wait until some NPC gives them a specific Quest to go to some place and find the McGuffin, or are they hearing about the troubles and sufficiently motivated to come up with some Action(s) themselves? For example, do the PC's know any of the victims? Are they part of Organisations that care? Did they have a Vision that helps leads them to troubles? They need some reason to Care, then they should take the bait, without need for an explicit Quest.
It's only a subtle difference, but it helps cultivate Player Agency, or at the very least the perception of that, which is all you really need for a far more satisfying experience.