The post I'm linking to below is kind of old and I'm sure that the contest results would be different today, but it should still apply for the purpose of improving your desktop workflow. Plus, even though the shoot-out was between Linux Mint desktop environments, the comparison includes MATE. So, I'd recommend trying each of the tests listed just so you are fully familiar with all of the ways to take advantage of drag and drop in the MATE DE. One thing not mentioned in the referenced post is that if you have Compiz running, you won't be able to "hover" something to be dropped over the workspace switcher applet (to automatically switch to that workspace) but the same functionality exists if you enable the Compiz addon that displays all of the apps running on your system if you allow it to be triggered by moving the mouse to the screen edge (or corner). Likewise, this can be done by allowing the mouse dragged to the workspace edge to "flip" to the next (or previous) workspace. Best of luck!