I want to build cobblestone generators on ALL my skyblock world islands, so that an unlimited supply of my favourite block is always a stone’s throw away! I can never remember where the water and lava go though… mind helping me out?

Here’s a quick tutorial I pulled up for your reference:
tutorial

Have fun, and thanks for the help!

Island 1:
puzzle-1
Solve on Penpa (answer checking enabled)

Island 2:
puzzle-2
Solve on Penpa (answer checking enabled)