The common meta, aka. what you get on https://www.factorio.school/ https://www.factorio.school/, is to mark inputs using constant combinators. Alternately, at l

The common meta, aka. what you get on https://www.factorio.school/ https://www.factorio.school/, is to mark inputs using constant combinators. Alternately, at larger scales a couple of chunk-sized (and absolute-tiled) railroad blocks will do nicely; the railway stations work as labels. If you dive even slightly into the (enormous) mod ecosystem, there's one that lets you make physical labels, at one tile per letter. (Text Plates, https://mods.factorio.com/mod/textplates https://mods.factorio.com/mod/textplates) Since blueprint tiling was added, it's become absolutely obligatory to make good use of them. Almost every blueprint should have at least relative tiling enabled. Note, the tile size shouldn't necessarily be the exact size of the blueprint -- it's often convenient to have tileable blueprints overlap slightly, and it supports that just fine by making the tiles slightly smaller.