In general, and especially when doing a lot of repetitive tasks like laying in replacement graphics, I try to avoid the use of the mouse as much as possible and achieve as much as possible with the keyboard.
One method I have used for some time now to achieve this and which has become muscle memory for me is to hit cmd + 0 or ctrl + 0 mac/windows to switch focus back to the timeline after doing something in the source monitor, or selecting something in a bin. It's always worked for me on windows machines and I'm pretty sure I recall using it up until just recently when it stopped behaving as expected on mac too.
Nowadays, or at least on the machine I'm using now, which is running Yosemite, regardless of where the window focus is active hitting this key combo causes the timeline window shrink in size to something completely unusable (and square shaped) and move instantaneously to the upper left side of the left hand monitor from its position occupying the full lower half of screen on the right hand monitor. Hitting home key combo restores it with cmd + ' but I'd really like to just have the original functionality restored, especially since the habit is so integrated in to my editing these days that it's hard to stop it.