Standards
“Be a yardstick of quality. Some people aren't used to an environment where excellence is expected.” ~ Steve Jobs
As a leader, you should have standards. You should have expectations that your people can and should do high-quality work.
But this is not something that your people will know unless you tell them!
Explain your expectations. Give people templates or processes for quality control. Provide ample feedback, both positive and negative, so that your people know when they are doing well and, if they are not doing well, how to improve.
(image source: https://www.brainyquote.com/quotes/steve_jobs_126246?img=3&src=t_leadership)