Is there a way to make Macs save a default folder to save to?

Make an alias to your Dropbox folder.
Put the alias in your Documents folder.
Now you're one click away, when starting in your Documents folder.

Or you can put the alias in the Sidebar, under Places, and you're one click away when starting anywhere.


If you don't know what an alias is, choose the Help menu in Finder and enter the word alias as a search term.

 

It depends on the program what your options are. A lot of programs go to where you last saved. From experience I know that Photoshop automatically goes to the folder where the original picture was stored.

I have several download folders for different programs. In their preferences you can set where they store the file.
Apparently you can set in Microsoft Word where to default save.

So I would check preferences if I were you.

If none of these options work, you could try to change the code of your program .

But another (pretty expensive) solution is DefaultFolderX.
You can set default folders for any program. (I think, I just scanned their website).