Hi myself and my husband are partners in a cleaning company, I began solo, like you, 18 years ago.
I have to go out in a minute but some key pointers:
You need to give clients a day, not a time, we never work to appointment, but they do need a set day to plan for your visit and to prepare the house for cleaning (ie pick everything up and not have family members home using the rooms on that day etc) they need a set day to plan for.
You need to decide upon a business model, ie will you sell it hourly or per home after quoting based upon size, number of occupants, pets , clutter etc.
You WILL be inundated with work once you are established as good and reliable (make sure you are of course). There is a shortage of domestic cleaning service in this country. Every cleaning service we know has been unable to meet demand after at least a year in business, it's finding the right calibre ofstaff that stalls the business in most cases (including ours!).
Price for the future - you need at least £15 per hour coming in if you ever plan to have employed staff, if you go for the agency model of hiring self-employed staff you can be cheaper but there are a lot of legal grey areas to be wary of with that model. You can start lower to get established but NOT MUCH LOWER - maybe £12 per hour with a view to creeping up to the necessary rate. Make sure you provide service the customer values, there is a lot of rubbish out there, offer the best in both quality and customer care, then you charge what you need to go forward in the future. Even charging premium rates we struggle to make a profit now we have several staff to fund, don't underestimate what you'll need.
Bring your own fresh cloths chemicals and equipment, it's an additional cost but you cannot do an good job with just what clients provide, they don't know what you need and their vacuums never work and they do not maintain these, maintain your own and bring it, learn about the chemistry of cleaning to identify the best chemicals for the jobs and bring these with you.
We are on the panel of a members association for domestic cleaning business,once you can prove you have insurance and are registered to pay tax you can join for additional support btw - pm me if interested in this help, it's free at the moment and has proved to be a huge support to all of us as we are able to pool our knowledge and help one another solve problems.