Making Money For More Rentals

[George Fox]

Hello everyone! I'm new to BP, but have been investing in real estate for a little while now, and have accumulated about a dozen rental properties in the past couple years. My problem is now I'm starting to run out of money for more rental properties, and am looking for ways to make more money to spend on rental properties via real estate. I currently making the money I live off of flipping a couple houses a year, but I don't flip enough right now to have extra to spend on rentals. I also currently have my real estate license. 

So my question is this: How would you guys start creating more capital to spend on rental properties via real estate? Should I ramp up my flipping business? If so, how? Should I put more time and effort into doing more real estate sales? How? Or what combination of the two could I use? For example if I was to start a direct mail campaign to start getting more leads, could I offer to buy their house but if we can't agree on a price offer to list it for them?  What else would you guys do?

I know thats a lot, but I'd really appreciate any advice you guys have!

To keep this beneficial, I'd appreciate it if you don't reply "it depends on your goals" (my goal is to buy more rentals) or "spend time learning" (I've done that and am doing that right now) or "partner with somebody" (I don't really want to partner) or anything else like that, I really just want to know what you would do in my situation. Thanks!