Hoodman Loupe and Hoodman Eyecup.
The Hoodman Loupe is a brilliant piece of kit! It says on the tin ‘For Glare Free LCD screen viewing’ and that is exactly what it delivers. What is the point of buying top-level cameras that sport 3in LCD screens with a million trillion pixels if you cannot view the screen in sunlight?
So many times at Wimbledon and other outside events I have seen pro photographers trying to view their screens by shading them with their hands but this is never effective. Use the lanyard to hang one of these loupes around your neck and the problem is sorted. It is not just a glare shield but has a proper German-manufactured lens with focusing and diopter adjustment.
Personally, I think Nikon and Canon should supply one with every camera but until then you will have to cough-up about £70 to get one.
(Incidentally, I found the Hoodman eyecups to be far better than the Nikon alternative but at £27 each they are pricey, especially if you have two bodies. Unusually, at about a tenner the Nikon part is a lot cheaper but the one I bought tore after only a few weeks.