Good-Person
Captain Junkie
The most important thing is for you to always listen to your body whenever you are doing any kind of job you are doing because your body is always going to give you feedback how a particular job is affecting you with the way you are carrying it out so that you will know how to go about it and adjust whenever your body need you to adjust so that your health is always going to be in a good place.
I work as a freelancer and I usually feel pain in the neck and shoulder when I work for long hours. The best way to counter this problem is take short breaks and this allows your body to take some rest and counter the effects of excessive sitting.