I have columns on a spreadsheets and enter receipt amounts in appropriate column as they happen during the year. All I have to do is print off master spreadsheet that reconciles all the monthly sheets and just copy numbers over to a schedule C. I then just stash the receipts away and forget them. I don't even sort them into different folders. If I get audited, that is the IRS person's job to sort it all out. Been thru enough audits to know all I do is put on the coffee and put everything on the kitchen table and tell them to have at it. I pay them to do their job, so they are not going to get any help from me. I will provide the coffee though.