I never knew about the 3 Finger Drag for Trackpads until a few months ago. Man do I ever like it. I am on my iMac most of the time (I do own a 2011 MacBook Air), but about half that time I am using a Magic Trackpad.
Why 3 Finger Drag
Here is the deal. Previously in the world of trackpads, either a portable version or standalone version, you had click and hold on an object and then use your other fingers to drag it around the Finder area. Trust me, that really was a “Drag”!. No more!!
Now, using the 3 Finger Drag method all you have to do is have your mouse over the object you wish to move, place 3 fingers on the trackpad and just drag it. No pressing down, no trying to manipulate something for long distances with your fingers all twisted around. There is a catch though. You have to activate 3 Finger Drag in the Mac OS. Here is how to do that in El Capitan:
Activate 3 Fingers
Go into your System Preferences and click on Accessibility:
When in the Accessibility window scroll down to Mouse & Trackpad in the left pane and then click on Trackpad Options:
Once you are in Trackpad Options you need to check “Enable dragging”. There is a drop down to select “three finger drag”:
Just click “OK” when you are done and 3 Finger Drag is activated.
If you use a laptop or standalone trackpad I think you will appreciate 3 Finger Drag. It takes a little getting used to if you have been doing the click and drag thingy for a long time, but trust me, it is really handy. Just one more reason to use a trackpad.