Broadly, these are the methods that I've found useful. I'll describe them soon :
- Yoga
 - Special Muscle exercises with squishy balls
 - Walking
 - Some daily routine changes , viz. sitting posture, work-breaks
 
The daily routine changes :
- While sitting on office chair, a normal person should also use a lumbar support, to maintain lordosis (the hollow curve of the back).
 - If sitting on a sofa, keep a pillow behind lower back.
 - If it's a chair without back, arch the back frequently to accentuate the hollow more.
 - Be conscious of your slouching posture everywhere, & correct it be doing the above.
 - Take shorter & more frequent breaks from work - use it for a small walk (outside preferably), tea-time, visit a colleague, make a phone call, or stretch.
 
