I make sure the designer's name is in the file name so I can give credit.
I combine bits together in one folder if I think they go well and rename the folder.
I find them later because I put them into ACDSee and tag them all. So when I click frames-wood at some time in the future that wooden box frame will pop up
Having said that, tagging in ACDSee does take a lot of time and probably requires a slightly obessive personality like mine!!
But I can't stand hunting through folders to find things. I adore my tagged collection.