I found that turning up the brightness to it's highest setting (I normal keep it at +1) makes a difference.
Hoodman Loupe helps ...
I find the same loupe I use for 4x5 works well for focusing if not framing. It's half the size of a hoodman, a plus or a minus, depending on how you look at it.
Waiting for a commercial detachable solution, I used a Rolleiflex viewfinder.
First of all, fasten the plastic protective lcd cover to the Rolleiflex viewfinder with scotch tape. Then you can put it on the camera or take it of in seconds.
Dimensions fits perfectly, and view and focusing handheld are spectacular.
_DSC1535 by sergio lovisolo, on Flickr
_DSC1536 by sergio lovisolo, on Flickr
I use a three sided folding hood “3 inch Pop-Up Shade” made by Delkin Devices and sold at B&H. It’s not perfect but helps block glare.