Starting out with your first rental allows you more flexibility, the more units you scale it would be wise to have a more thorough and consistent process.Cash:  Most people will advise against cash because it's hard to track and inconvenient.  11% of American's don't have bank accounts though, sometimes this might be your only option. 

By your own account you are executing the purchase of your new properties before you execute the sale of your old property. 

California Code, Code of Civil Procedure - CCP § 580d(a) Except as provided in subdivision (b), no deficiency shall be owed or collected, and no deficiency judgment shall be rendered for a deficiency on a note secured by a deed of trust or mortgage on real property or an estate for years therein executed in any case in which the real property or estate for years therein has been sold by the mortgagee or trustee under power of sale contained in the mortgage or deed of trust.

The hardest part is execution.

Build a game plan to suit your individual goals and execute.

When you execute your option (if) you'll do the usual Purchase Agreement which would replace the original (payoff) loan just like any other PA would do at that point.Keep in mind, the Option Consideration you would pay for the Option Agreement is just that...full payment of the OA...and NOT a down Payment on the property.

They've helped me on a project and had great execution.  

Unfortunately, most Americans don't like calling a spade a spade so we refer to these transfer payments as Fannie and Freddie.  

And what methods do you do to execute on them?

But there is a way around this problem.The first step is to get your financing in your personal name then use a land trust to execute any transfers into your LLC or Series LLC asset-holding company.