How do investors often manage the flow of funds for cash flow

[Mason Blake]

Very tactical question, here. I am curious what people are doing with the flow of funds from cash flowing rental properties. A few questions here:

1. Do you setup completely different bank accounts for collecting rents and making payments? I will have an LLC, so this is currently my plan
2. With the calculations accounting for vacancies, repairs and the "sometimes" expenses -- do you just hold that cash in a savings account? 
3. If you were cash flowing a $200-$300 per door on your properties, how are you "paying yourself"? I'm not sure I would want to pay myself anything but in the case of a single-member LLC I suppose it wouldn't matter, right? I can just make a transfer or cut myself a check.

My thinking behind these questions is that I want to make sure separate my operating account from cash accumulation that I can then use for more property acquisitions. 

What do others do here?