Going to Thistletop (Spoiler)

[Mootaz]

Maybe I've missed it, but what clues do the players have to decide to go to Thistletop?

They are at the glassworks in chapter three. But how do they know to go to Thistletop in chapter 4?

[Assembler]

Tsuto's journal is the key. It says Nualia burned Tobyn's remains in a Thistletop shrine and is working with Ripnugget (edit: the chief of Thistletop) in planning another raid.

[Mootaz]

OK, that explains it. The German version does not contain the word "Thistletop" in the journal. It only says that Nualia burned the remains, but not where.

[Lawrencelot]

Most of these questions are answered with notes and journals in this AP, which some GMs (and players) find a bit boring. Off the top of my head:

-going to Thistletop: Tsuto's journal
-going to the Misgivings: note from ghast in the farmlands
-going to Turtleback Ferry: Xanesha's letter
-going back to Sandpoint to defend against giants: Barl Breakbones' notes
-etc.

I think these are more for when you don't have anything else as a GM to steer the players in a certain direction. If your players have certain motivations, you could use other things like NPCs to steer them in a certain direction. In the Thistletop example: maybe have a guard NPC tell the PCs that they saw goblins go north-east, or sailors who saw goblin activity increase near Thistletop, or rumours of gold and treasure in that area, etc. Also, if you can somehow tie in the PCs backstory to go in a certain direction it's even better. But all of this can be a lot of work of course, so it's good to have something as simple as a note to fall back on.