[TriLUG] Dropbox and folders (directories)

[MvER - TrLUG via TriLUG]

Dear TriLUGers,

On my laptop I have been keeping several folders with files.
Some of those files/folders have been placed in my Dropbox account.
This creates additional folder on the laptop, named (surprise) 'Dropbox'

I have been doing this 'double-tracking' on the theory that having two
copies is giving me security against loss.
OTOH, it creates the issue of which file do I work with and then how do
I be sure to synchronize it to the corresponding folder (Dropbox or laptop)?
Do I need both?

Your best practices, please?

Thanks.   Mike R.