Today even too many cameras have a rear LCD that can move up, down, right, left, 180, 360 degrees… My old Sony NEX-5 would only go up to about 80 degrees. Self-portraits are hard, especially with adapted lenses that do not autofocus.
I solved the issue with a something made of four elements: a flat rectangular mirror (Boots chemists have one or two purposes…) and three Manfrotto items:
The photo shows how the three Manfrotto items place the mirror at an angle such as the rear Sony LCD is visible from a position in front of the lens.
The self-portrait of my jacket is the first product made so!
An alternative would be connecting via HDMI the Sony’s output to a simple TV set.