I have a folder with all my work in it with me in the van. Each page has a line of 12 rectangular blocks going across the page, and each line is a customer. I write the date the clean was done in the rectangle and once i have been paid for it, i fill in the rectangle with a green highlighter. I also have a diary with me in the van which i fill in at the end of my day, which would be, which houses i have done, whether i got paid cash or cheque, or did i leave an envelope, or do they pay online, that sort of thing.
At the end of the week i do my banking, usually on saturday. This involves writing everything i have taken in, that week, into my 'takings' book. Everything is dated, and is separated into cash, cheques, and online. This book stays at home.