Even as a humble airframe driver I always try to look after crew. I used to work for a full service airline and whenever we had crew from either our company, or other companies, positioning in uniform I would make a point of asking the No 1 to upgrade them if we had space available: if we didn't I would always go and explain, personally, that we just didn't have the space today.
If I ever saw one of our staff, ground, aircrew, whoever , getting on board I would always get out of my seat and go and greet them, and again check on upgrade availability.
Just a courtesy.