In daylight the image in the display of a digital camera is hardly visible. In bright sunlight it impossible to use it all. There are some shades for sale already. They can be attached with velcro or with double sided tape. They have one thing in common: they don't come cheap.
Here is my solution: a slide viewer.
I sometimes use the display of the Ixus SLR-style, with the camera at my eye.
The chinese viewer on the left is from B&H: $ 0,95. In China they can be bought as a keyring. A printed company logo is included in the price. If I were Canon...
The Kaiser viewer on the right costs euro 5.50. It is a copy of the old Agfa Gucki!