I have some background images or patterns loaded into the WP Media Library. I use these in DMS sections or components. As far as I know this is a good way to handle these (best practices?). For layouts I use the front-end design tool mostly (because it's awesome)...although occasionally I do build a quick page in the WP page.
When building a page in the front-end editor the assets don't show up as "attached" or uploaded to any page. When doing very many pages or using many assets this can get a little confusing. Is there a way to add what page the asset is attached too?