All Collectibles in order as they appear. The characters used are just examples. Of course, you can use whatever character you like with the according abilities ;-) :
Part A: Rathtar Caverns
To the right, use the dark force to open the cave and get the Minikit
Still outside the main cave, use the agility poles to get from left to right. Then use grapple to pull open the wall. Build the Minikit.
Use the force on 5 glowing flowers
At the waterfall there's a small entrance to the left. Go through and all the way to the top.
Go through the hatch at the bottom left.
Build cupcakes for the spiders to the right and climb up.
At the top of the waterfall, dive with Ackbar.
(Unlock Ackbar at the "Poe to the Rescue" Mission)
Part B: Loading Area
Before entering the shootout, go the the left and open the flower with the force
Same place, shoot the gold Lego Rock
Destroy 5 glowing plants in the Rathtar area
Pull down the box with grapple