If the picture is to be viewed on a small or just HD screen it is simpler to take video and then extract the frame you want. I just set my mobile to video, start recording and prop it up somewhere. Then I essay several different poses at different distances. Then I stop the video and open it in Google Photos. Now I can use the edit function to save whichever frame turns out best. I don't need to hold a pose or enlist the help of anyone else.
Here's one taken that way today in Ulverston, Cumbria:
