Below you will find a list of player-submitted optimized layouts for solving different portions of the production pipeline in DSP. If you have a layout you'd like to submit, go ahead and add it!
Discord/Steam user Falk has created a guide on Steam with several great layouts:
Production Line Spreadsheet
This Google Sheet (currently incomplete) helps you plan the structures and ratios necessary to produce various elements in the game. To use, select "Make a copy" from the file menu after opening.
The Conveyor Belt Mk.I can carry 6 items per second or 360 items per minute. A Mining Machine that is covering exactly 6 veins will produce 180 items per minute. Combining the belts from two mining machines will fully saturate a Conveyor Belt Mk.I with a full 360 items per minute. Note: Mining machines can cover the same resource veins, as shown in the picture below. It is also worth mentioning that later on these numbers will change through the "Veins utilization" upgrade.
Reddit user u/oldshavingfoam has created a number of excellent layouts.