I found this the hardest thing to get right. It took me two years before I got any good at this. So I will share my experience and hope this will be helpful for you.
What is challenging is to get the job done properly and within the agreed allocated time. As a general rule of thumb in a typical house, I will spend at least 15 minutes in each room. I will often take longer in bathrooms and kitchens. A large kitchen can take an hour just by itself – the same with bathrooms. There is a lot to do in kitchens and bathrooms so make sure you allocated the right amount of time to that.
Ask your client, where possible, to leave the property tidy. I have on many an occasion gone into a property (a playroom, for example) and it was in absolute chaos. So before I can even clean it can take me 20 minutes out of the agreed hours just to tidy – and that can put you under tremendous pressure. This means you will have less time to spend on the rest of the house and in turn means that it can leave your client dissatisfied, even though it is not really your fault.
The other thing is – if there are tonnes of washing up left, it can easily add 15 minutes to the clean, leaving less time for proper, core cleaning.
One thing that I always try to cover with clients before signing the contract is explaining that ideally we would love them to leave everything tidy. However, if they are really busy and want us to do tidying up, that is not a problem at all – but either we will need to go over the allocated time or, if that is not an option, some things will not get done.
You can let them know at the end of the clean – perhaps by leaving a note – that these are the things you did not manage to do but you will cover them next time.
I think it is very important to demonstrate that you will do anything to help but you are only human and you need to have the right amount of time and resources to have the job done right.