>>11147338Litematica is a pain in the ass to set up and use, but it makes building stuff in survival a lot easier.
It basically lets you create "schematics" of structures you select with a tool (a stick by default) and display them as a hologram that shows what blocks you need and where you need to place them.
It also gives you a list of materials you need to complete your building
It's useful because you can test out build ideas in creative until you're satisfied, then create a schematic of it and start building it in survival.