This hint is an oldie but a goodie, and we could only find it mentioned in comments on older hints. If you don’t know it, you’ll want to; if you already knew it, pay it forward to Mac users who are spending too much time fussing with the mouse.
The Apple menu sits at the top left of your menu bar, and the Notification Center icon sits at the top right. For years, though, OS X has made clicking menu items in either position simpler than it might appear. You needn’t move the mouse cursor to precisely the slim confines of either icon when you want to click on them. If you slam your mouse all the way to the top left corner of the screen, well beyond the perimeter of the Apple icon, and click—you’ll still successfully trigger the Apple menu.
The same trick works with the Notification Center menu at the upper right: Move the mouse all the way to that corner, fretting not about whether your cursor is actually atop the icon, and your click will still register as desired. …
Source: Mac OSX Hints