Dive summary:

• If you grow your business, you will not be able to visit every job often enough to oversee the quality of all the work your crews are doing, so put your standards on the job site when you're not.
• First and foremost are foremen because it is hard to overstate the value of finding, training and keeping good foremen who can push crews to do what you want done.
• A couple of other options are surprise inspections, if you have time to get into the field, and requiring photos or videos – almost any phone now can produce those – on a regular basis to let you see what's going on and to keep in everyone's mind that there's your goal to meet.

From the article:

Mix and match your approaches for driving quality. Different approaches will work for different crews. ...