Cross-posted from this thread:
Ultimately, the goal is to provide enough context so that the players can make meaningful choices, and then resolve the consequences of those choices. This, in turn, creates new context for another set of choices.
Not acting is also a choice. In my experience, when players are having a hard time deciding what to pursue, it is because they lack the context to make meaningful choices. There is absolutely nothing wrong with devoting a session to providing context. NPCs have their own motivations, and can certainly urge the PCs in one direction or another, dropping context along the way. You have three hooks? Three NPCs/NPC groups are trying to direct the PCs. Still their choice, but not they have more to go on. Say one of those locations is site-based. One of the NPC groups could simply be a rival expedition to that location. adding a contextual time limit. Or not, if the rivals are wiped out. There may also be a time consideration to making a choice, because previous actions have made enemies, and sitting too long in one place allows those enemies to take action.
It is also useful to have a tentpole in a sandbox - something obvious that the PCs can do while they mull over their options. In the old days, with fantasy games, this was usually a megadungeon. The megadungeon provided a site-based location with a pair of intertwined obvious goals - explore and carry back as much treasure as you can, There is no reason why a huge Mandate base carved out of an asteroid couldn't serve the same function.
You will see comments in this thread where most players say they want a sandbox. My experience is very much in agreement - the vast majority of players want to drive the campaign. They do, however, require context as a form of road map to decide where to drive to, and context can be both toward a goal and away from a previous consequence.
These players also want a story. Stories occur in the sandiest of sandboxes and the choo-chooiest of railroads. The question is: how much agency do the players have in choosing what that story is? The sandbox allows the players greater agency, but requires that they use that agency. Provide enough context as both carrot (opportunities to be had) and cattle prod (those who wish the PCs harm due to previous choices) and, IME, the vast majority of players will start making plans of their own.
(Related to this, when the players start talking about what they would like to do/find, even if it is not one of your hooks, take advantage of that. Use what they want as part of your adventure design; include some hint of that in your hooks. But consider offering multiple things they want at the same time, so that they have to prioritize, and thus are still choosing what to follow rather than having it be handed to them. In the long run, having more things to pursue than you could ever follow up on is better than having too few options.)
EDIT: I forgot to suggest: When you are creating your adventures, be sure to include hooks to potential future adventures you may wish to run. If it seems that A hints at B, C, and D, then C hints at B, D, and E, then B hints at C, D, and E (allowing them some insight into C, which they have experienced), most players will begin looking for these bits of context, and use them when deciding what their PCs should do next.
IOW, consider what threads link your sector together as a whole, and don't be stingy giving clues about those threads when designing adventures.
