If you work in a Linux desktop environment/windows manager like KDE, Gnome, IceWM (and probably many others), you definitely should try the following mouse trick: click/drag while holding <alt> above a (not maximized) application window. Depending on the mouse button and the windows manager this should move or resize the window. It's way easier than aiming at those thin window headers and borders.
For example in KDE and IceWM you can do the following:
- holding <alt> + left mouse button drag: move the window
- holding <alt> + right mouse button drag: resize the window (by moving the closest border(s) your start dragging from)
- holding <alt> + middle mouse button click: move the window behind the visible windows (be aware that the window remains in focus although it may be hidden by others)
In Gnome it's a bit different:
- holding <alt> + left mouse button drag: move the window
- holding <alt> + middle mouse button drag : resize the window (by moving the closest border(s) your start dragging from)
- holding <alt> + right mouse button click : invoke a window managing related context menu
Once you're accustomed to it, you'll find it hard to live without. At least I do when I'm forced to work in MS Windows from time to time.