Not to be a bragger, but this is what my Download folder looks like.
There is one file in my downloads folder (it belongs to my son). The only reason it's there is because I need to see if it's a file he needs (otherwise it's to the trash!). Now I'm not saying your Downloads folder needs to be as empty as mine, but I recommend emptying it out, often, so it doesn't fill up. Another reason to empty the Downloads folder, is that Finder has a place for your all your files. If you are familiar with Finder, you'll recognize that there are numerous Folders. A folder for Documents, the aforementioned Downloads, Movies, Pictures, Music and a few others (my finder has folders for Box Sync, Copy, Dropbox, Google Drive. These are all cloud apps that sync directly to my Mac via Finder). If you use any of those cloud drives, your Finder may have those, or other folders.
Now if you think about the types of files you are likely to have on your Mac, they probably fall into one of the following file types that have existing folders. For instance if you download a document (Microsoft Word, Pdf, Pages, Excel Spreadsheet, Keynote presentation), it should come as no surprise that I would recommend to move those files to the Documents folder. Similarly, if you download a picture or movie, those files should go into the Pictures or Movies folders.
Quite often lately I've happened upon clients with Download folders that have multiple versions of the same download. As I mentioned earlier in the blog, this happens when you download the same file multiple times. What happens is your Mac adds adds a number to each subsequent download. So if you take my Downloads folder (above). If I had downloaded the FinalPersonalReflection.pdf file multiple times I would have the original (as it is), then if I were to download it say 2 more times I'd have a FinalPersonalReflection 1.pdf and a FinalPersonalReflection 2.pdf. Make sense? So my advice to you is this. If you think you've already downloaded a file, check your Downloads folder before you download another (unnecessary) copy of the same file. If you have multiple versions (or copies) of the same file, delete them, no reason to carry more than one copy of the same file. When you've deleted the duplicates, make sure you Empty your trash! A great way to help speed up your Mac is to remove unnecessary files (like duplicates in your Downloads folder), and to Empty your trash.
I hope this helps, and this is a lead in to my next blog, where I provide ideas on how to manage your files within their respective folders.
I hope this help you out, and until next time, best to you and your devices!