You have to drug test and these are expensive.

It is very easy to find a lab that will do a test. 

I haven’t gotten to a point of testing environmental factors or having a Perc test done yet, because...

They also do stress tests.  

If they can't, you could test yourself by driving a long thin nail through the drywall that covers the firewall and see if it hits "something really hard" about 1-1/2" in.

Again, the kids were usually not particularly good at doing what needed to be done for them to pass the tests I was preparing them for.Whatever socioeconomic level the people I worked with were at, I never saw a Greek boy with an absent or mostly-absent father do well.

Begin with a small daily budget to test performance, then scale up based on results.

Bring in trusted authorities to inspect, test, and make you informed vs guessing. 

I've been listening to bigger pockets since January of this year and after exploring all the different avenues to get started I have decided to test the waters with rental arbitrage.

If you want to test the waters on whether your property would be a good rental or not.