Its not often that the sales person is also very good at management.

I’ve bought some houses with 0% interest for a year credit cards and a few with consumer lines of credit from banks.

With the exception of building a trailer on the property (these are hard to finance), this sounds like a good plan AND if you are using it for your business AND your business pays more than 50% of the rent (if you have more than 1 tenant), then this is a more financeable property in the eyes of banks and credit unions as it would be consider a commercial "owner-occupied" property. 

However, I think for the average person this is probably not true. 

Meanwhile, bank money market paying 7.5%. 

.- If you decide to have an LLC for each property, creating a Management LLC that all the other LLCs "hire" to run their books, will allow you to only require a bank accont for the Management LLC.2) You may not be able to do a Trust.

Strategic renovations don't have to break the bank.

20% down, mortgaged the rest through a local bank How did you add value to the deal?

Most banks won't want to come in with a line of credit that is second lien on the property.

As you progress your bookkeeping business, you'll likely want to learn how to export statements from a variety of property management platforms, as investor books are housed in bank accounts, spreadsheets, and a variety of property management and accounting software!