I am trad, so the method used here doesn't apply, but the mental approach may.
I always take as long as I need to ensure as near perfect a finish as I can achieve. If that means I take an hour and 20 minutes, or double that on a small property, it makes no difference to me. My reasons are that I see the time I spend on a first clean is an investment in the customer. I see every new job as a one off unless the customer requests a regular clean, so I may or may not get the job on a regular basis, but whether I do or not, I often pick up work through recommendations or walkups because of my attitude towards my job and the value for money I offer.
I'm not being boastful at all because I don't see myself as better than anyone. It's simply my modus operandi and with my 21 years in this game, it has served me very well.
John