How can I copy files from my Mac to PC via Microsoft Remote Desktop?
When copying files from Mac to PC using Microsoft Remote Desktop I prefer to share a subfolder, not the entire drive.

Here's how:


In Remote Desktop on your Mac select your PC in the "My Desktops" section. 
Click the "Edit" button (pencil icon).
In the popup click the "Redirection" button (folder icon; see image below).
Check the "Enable folder redirection" box.
Click the "+" button at the bottom of that window and browse to the Mac folder you want to share.
Connect to the remote PC. 
Look for your shared Mac folder in your PC's "My Computer"
directory (see image below).





Finally, as noted by @Bart and @robbpriestley in the comments below, if you are already connected to the remote computer you need to re-establish your connection in order to see the shared folder.