So I highly recommend to watch the related video about stretching on fabulous channel on YouTube or any other sources.
In and out : where "in" is inflating and "out" is releasing.
remember when you stretch your body, you need to release it eventually.
Note: Certain joint conditions, such as hypermobility, can be worsened with stretch exercises. If you have a condition that causes your joints to be looser than average, especially if you're on the more severe end of the condition, avoid routines that focus on flexibility. For these individuals, it's better to focus on strengthening muscles around your joints for support, and stick to light stretches to keep from being stiff and to get circulation going.
Pilates and yoga moves help me a lot to stretch my back without incurring into injuries.
You can start with 5 position that get to stretch the whole body . Hold the stretch for at least 30 sec
Also, I like to do what are called spinal hygiene exercises to move and stretch my spine in every way it can – I’m prone to back pain and doing these regularly helps a lot. You can find different versions of these online too, but basically anything that leads you to gently flex/extend/rotate/sidebend each part of your spine (lower, upper, and neck) should do the trick.