Win10 makes it easy to automatically empty the Recycle Bin and Downloads (but sadly, not other locations). One major PITA is that Firefox does not use the standard Downloads folder/directory, but has its own. It's configurable, of course, but I never remember until I've already got a zillion things in it, and I try to run everything with a minimum of customization.
Firefox defaults to remembering where you last downloaded a file for each site. This is useful for things like image sharing sites when you always want to drop pictures into your pictures folder, but you can disable it and always use the default downloads folder.
In about:config, set 'browser.download.lastDir.savePerSite' to false (you may have to create the preference), set 'browser.download.useDownloadDir' to true, and set 'browser.download.lastDir' to your preferred location.
