1st, I agree w/ Sean's review about the LCD viewfinder loop - what a benefit.
The only thing I did was order an inexpensive extended eyecup and then found a piece of plastic for a spacer and simply screwed them together.... carefully and all lined up. The screws are very small - the idea is that they break before the camera does.
I use the "Perfect 3x" which folds open so you can use as a simple sunshade.
Very handy in video shooting and w/ magic lantern loaded, the focus peaking is just so darn easy to use.