Hey, welcome!!!! I, too, am a bit OCD about cleaning, and that is precisely why I got out of being an RN nurse and went into cleaning. I love being on my own, being my own boss. I have no employees and dont want any. I take a lot of pride in my work. When I was a beginner, I made a lot of mistakes. But you learn from each one and over time you will find your work has become more efficient and much better. Be open to suggestions, either from other pros OR the customer. Customers want to feel that you listen to them and are willing to try whatever will get the job done as long as it is safe and healthy for you to do. When I start a new job, I ask the owner: "When you look around your home, what screams 'Ineed to be cleaned!'" Is it dust? Grubby floors? Dirty counters or fridge or whatever?
Be aware that a normal, standard cleaning does NOT usually include things like laundry, making beds, cleaning ovens, or emptying fridges to thoroughly clean them. Those are usually considered extras, because they add on a lot of time. If from the start, you agree to do these things, make sure the customer knows they DO add on time, to their bill. If they can only afford, say, 4 hours, maybe a 1/2 hour will be taken to do those extras. Some people here use a pre-printed checklist...to give to the client, which explains all this. I am considering doing this, but for now, rely on my skills at communicating. I do think a written check list is a super good idea, though. If it's in writing, no one can honestly forget!
Keep asking questions. This site has a few too many people who are here only to promote their own businesses. Tiresome! But there are also people here who do want to share ideas and info.