I think the key is to have at least 100 projects underway simultaneously this way when a project is paused to look through the scrap pile you nearly always see something that you realise will be perfect for another project which was paused several months ago waiting for inspiration/the right bit of scrap. i dont throw stuff away unless it is attracting flies or made of a material i dont like or is too rusty to weld then it goes to the scrapyard and gets traded for something else.