Build a 5 by 5 structure ( make sure you have the space ). Fill it and add another layer only on the exterior.
For a very quick video check the one below:
Timestamps:
00:00 Intro + Grid
00:44 Propelled Achievement
00:55 Now that's inspiring, Who goes there Achievements
01:16 Captain Achievement
01:29 The Gardener, Sculptor Achievements
02:14 Architect Achievement
02:30 Every block matters, Opulence Achievements
02:56 Rome wasn't built in a block Achievement