"I have sore heels...but I spend most of my day sitting at work!"

 Increasingly I am hearing this, and likely even more with makeshift working from home areas during #lockdown. 

Check out the link below for proper positioning (ergonomics). 

Also, if you have sore heels...no barefeet please, even on carpet! 

Try your thicker soled, most supportive shoes for a start. 

Ensure they are not slopping around on your feet (looking at you here ugg boots!) Also, regular calf and hamstrings stretches.

https://www.safety.uwa.edu.au/topics/physical/ergonomics/workstation