Minecraft wiki entry for Redstone_tips, associated text: A complex redstone project for a Survival world can be designed in Creative mode first, before investing resources and effort in a survival world. It's handy to keep a creative-mode world handy for such laboratory work, usually a superflat with cheats on. You can also manipulate the game rules for your testing world to your liking, such as to make it permanent day or avoid mob spawning. Creative mode is great for building, because you have an infinite number of blocks, you can break blocks right away, and you can fly around to look all around your structures. You can also press F3 + N to invoke spectator mode, then fly through look inside your circuit.