How do you organize your portfolio finances?

[John Fider]

Does your entire portfolio go into 1 bank account? How do you know how much money is allocated in each property so as to not use up funds you saved up for rental A, to pay for rental B's expenses? How do you keep it all straight? Do you have everything mixed in with your personal finances?  I appreciate any advice. 

My goal is to organize my portfolio finances so I can determine at a glance if I have enough money saved up for upgrades for a specific rental... or quickly determine if I did not allocate enough funds for maintenance for a specific property at the end of the year.