The first thing you need to find out is your normal sitting position. It is difficult to find out by yourself so look at your sitting in a mirror or ask your friend to tell you. This is actually important, because if you don’t know where your mistakes are, you can never correct them. Especially if your position is one of the following ones, you need to change it ASAP!!
The Wrong positions
There are three important positions that are not good for your posture:
Hunched forward position
Upright position (900)
What you should strive at are these positions:
The Right positions
Sitting perfectly straight is not good for the body, then what will be? The answer is simple, and you can even choose from one of these two positions:
Relaxed position 1000-1350
Relaxed position 1200
This way, the less effort you feel while sitting on your chair, will be the best position, because your spine will not feel the effort. And the best positions are the ones from 1000-1350. I know it is hard to make it your habit right away, but the more you practice, the faster you will meet the best results. Take care of your body.