Many great pieces of advice here. I love watching the talks at GDC (Game Design Conference). I remember, though not in which talks, they mention tricks for precisely that.
I think these ones have been mentioned above, but these are the ones I remember from the top of my head:
- Grey out impossible choices (as opposed to hiding them) so that players know there are more paths and that previous choices have made a consequence.
- Choices should have at least one immediate effect, and preferably one long term effect. Make sure players know that something is happening in consequence of previous choices.
- It ok to have some flavour choices that neither alter stats nor change the story branch. It is generally preferred to having long intervals between choices.
- Each choice moment should preferably have no more no less than 5 options. I know people will dispute this. I think the key word is preferably. And the guy who gave this advice is from Inkle (if I recall correctly). So I think there’s some weight to this.