I guess it heavily depends on how you `hold' the widget in the first place. Lets say for instance the widget is called desktop command widget. Normally these are bar shaped, so to drag them to the bottom right of the screen, you'll need to press and hold by the left most part of that bar before dragging it down to the furthest right you can get to.

If you have a problem with doing that or if you're dealing with icons, you should probably use a stylus and again repeating the steps above. Remember as long as the object being used to put pressure onto the screen should be preferably to the opposite side of the widget should the widget be needed to be placed on the desired location.