Hiya,
This a very interesting question, and one that I can honestly say that we will not find all the answers for. After all what is the benchmark, your clean could be my dirty and vice-versa....
The reality is to accept that most staff want the highest rate of pay, for the least amount of effort. Off course you are gonna have your "star " performers, but these are few and far between. When you turn this around to the customer, they want the best standard of work for the least money.
My wife and I use a varied approach, as we feel that it is the best way to keep both the staff and customers on thier toes.
Each and every account that we have has a job sheet, which is drawn up with the owner/agent. This covers the basics, but also things like owners pet hates etc's. We make sure that each and every cleaner has the fact sheet, each and every time that they visit to clean. Spot checks are carried out on an ad-hoc basis, and never the same property on the same day/time.
Finally, and I personally think that this is the best way, it's the good ole dog and bone. We regularly call our customers to make sure that they were happy with the clean. The call shows that you care, and many of our customers have commented that more companies should do the same.
The only thing I would add is making sure that you follow up complaints. For example, if a customer commented that the cooker was left dirty, this would be the priority job on th next visit, and so on..........
Just my thoughts
Regards
Paul