Space allowing, I'll prefer to get everything in it's whole form. I'll set up a chest or several outside a POI to store things.
Space disallowing, All iron things get compacted into plain iron, all lead to lead, wood and stone get tossed, nitrate and coal get tossed. I'll avoid scrapping brass to brass though if I can help it, and will toss lead first
Basically a systematic order of valuing- Anything I can easily harvest gets compacted or eventually tossed in favor of other things.. Iron, Lead, Nitrate, Coal, Wood, Stone, Clay, etc.
As I get a bigger inventory to ferry things, I stop scrapping things. So, once i get a bigger vehicle, or once i get a drone, i'll scrap less and store more.