here's another exercise i recently started doing: bridgeπ
as you can see, still lacking flexibility in shoulder and back
but when you do 2-3 of those for as long as you can hold, your posture will instantly improve
here's a quick video for my fellow π¦ suffering from neck pain / forward head posture
1) lay on your bad tummy forward and head above the bed edge
2) breath slowly for 2-3s in and out, do that about 10 times (you will already feel your neck decompressing quite a bit)
3) move head upwards and downwards 10x, hold top position for 1-2s (=stengthens neck muscles)
4) do this 1-2x per day, 5 mins per session
i have a fairly long neck, so have had multiple neck sprains and almost daily neck pain over the years
after i started doing these, headaches from neck pain basically gone and generally feel having better posture