Use a business account for all business transactions, exclusively. Use a receipt manager that connects to your bookkeeping software to attach receipts to expenses. Use a real bookkeeping software (not a spreadsheet, I beg of you) to track all of the expenses. Stessa is acceptable when you have a small portfolio, upgrade to Xero when you have more properties. An investor specific software that includes bookkeeping alongside tools to manage rentals is also fine. Have your pro check your bookkeeping file for questions and errors at least quarterly, making sure to schedule a little more thorough review in December to prepare for tax season.
I use software that is specifically designed for property management. It tracks just what I need...my expenses in categories for reports and my cams etc. It is better than anything I have found.
@Account Closed, I haven't heard of Xero before; I'll check it out. If it doesn't have an existing connection to a given financial institution, how do you get transactions into the system from them?
Xero uses Yodlee to bring in feeds from most banks. However, if your bank doesn't connect, I recommend downloading the monthly statement in .QBO format and uploading it to Xero. It isn't quite as convenient as bank feeds, but its much easier than manually inputting them, or trying to utilize spreadsheets.
My approach is very similar to @John Underwood. Only two differences - I do my own taxes, and at some point I switched from a spreadsheet to Quickbooks. Spreadsheets worked well enough for 5-10 properties, beyond that they become cumbersome.
I use the desktop version of QB, not QBO. Takes a while to initially set it up, but once everything is set up it is quite convenient.
Any advice on how to set up Desktop QB 2018 for real estate investing?