A useful feature of pre-El Capitan versions of OS X was the three-finger drag. This was an option within the Trackpad section of System Preferences.
Amongst other things* it let you move windows by positioning the mouse cursor over the title bar and dragging three fingers on the trackpad (not clicking and dragging). You could also drag files from one place to another with three fingers.
In the best traditions of Apple’s continuing OS development this feature vanished in El Capitan… But it turns out it’s moved to the Accessibility section. Just click the Accessibility icon in System Preferences, select Mouse & Trackpad in the list on the left, click the Trackpad Options button, put a check in Enable Dragging, then select Three Finger Drag from the dropdown list alongside.
Notably, three-finder drag in El Cap isn’t quite the same as the old days. Because it’s now an accessibility feature there’s a slight delay when you lift your fingers, during which the feature remains active. In other words, drag a file somewhere via a three finger drag, then lift your fingers, and the icon will still be in move mode for around a second. Give it a try to see what I mean. However, this doesn’t impact too much if you simply use three-finger drag to move windows around.
* Here’s what I wrote in Mac Kung Fu about three finger dragging a few years ago:
“Three Finger Drag has several useful features, as follows:
- Moving windows: You can move windows by positioning the mouse cursor over the title bar and dragging three fingers on the trackpad.
- Coasting windows: Place three fingers on the trackpad when the mouse cursor is over a title bar and move it a little. Then leave two fingers permanently on the trackpad and flick with a neighbouring finger – the window will “coast” for a while (think of a puck on an air hockey board or of flicking within a list on an iPhone/iPad screen).
- Copying files: In Finder windows, if you position the mouse cursor over a file or folder and drag with three fingers, you can copy it to a new location instantly (hit Esc to cancel if you change your mind midway through). To drag long distances, lift one finger so that two still touch the trackpad, and flick that finger to “coast” (try it and see).
- Downloading web images: When viewing web pages, position the mouse over an image, drag with three fingers on a picture, and copy it to the desktop or to a Finder window.
- Selecting text: You can select text by positioning the mouse cursor over a sentence in a paragraph, putting three fingers on the trackpad and dragging.
- Selecting within a list: Drag three fingers across a file listing, and you can rubber-band select them. The same applies to dragging three fingers within any other list within OS X, such as the Inbox in Mail.