Put assets from asset store in sub folder

Moving around assets to different folders can break assets depending on how the asset references other files. Once you've fixed any issues in code or otherwise for each asset you move, you also run into the long term problem of what to do when an asset is updated on the store. Updating is not nearly as clean if you've moved the asset, and you'll have to repeat any fixes you did the first time with the new updated asset.

That's why I take the reverse approach. I put all my stuff in just a few folders, and leave the root of the assets folder to be the wasteland of everything I imported that it is. YMMV

It's generally considered best practice to import any assets from the store first into a blank project. From there, you can rearrange the folder structure, remove any demo scenes or other unneeded files, and then make a "clean" export to bring the assets into your main project.

This is really annoying and breaks the workflow. I usually just do this:

 -Assets
     -MyAssets
         -Scenes
         -Materials
         -etc...
     -AssetStoreAsset1
     -AssetStoreAsset2
     ...