Depending on the lead It can wear you out pretty quick try knocking in short spurts and follow up till you have a system down.  

I'm in the process of developing my business plan for the purpose of finding and acquiring buy and hold single family (possibly multi family), for the purposes of building a passive income stream in and around Houston...

How much can you rerent for versus the lower rent amount? 

I normally have buyers who are usually more concerned about the livable square footage of the lot versus the actual lot size.

For example, things like a source of heat (furnace) in the wintertime, a working water heater, working plumbing/electrical systems, etc.

Then you can play around with what the system sends you. 

Our attorney is Jeff Ehrlich (he has a Court St office), and we loved how he navigated us through BS versus the norm.

It's much easier to invest with confidence when you have a support system that you can utilize. 

I also own three properties that are appreciating versus just one.

As a vague, broad and more of a science fiction reference we have the sun that is continually putting inputs into our system and entire planets that are within reach that dwarf the resources that we have.