I got suckered into one of those '30-day-trial' thingies with Tim Mai and when I tried to cancel before the thirty days were up, I came up against emails that were not answered, phone lines that never picked up and chat requests that just hung in limbo.

We also had 0 responses out of 300 mailers  that week (and over the next 3 months we only had 1 call back), so we did a bit more research and saw how competitive the wholesaling landscape was in Seattle, and we just didn't have the time and energy to do trial-and-error to find the sweet spot.  

It takes years to build the right team, especially developing relationships with contractors, do that as you need them, trial and error.  

In the end, we ended up selling (for 1.3m), taking the proceeds and using them to to purchase two properties, both in Brooklyn as well.Shoot me a message if you want to talk - happy to point you towards the mortgage broker we've used with great success in the NY area or just give you a bit more detail on the trials and tribulations we've faced in Brooklyn which is a vastly different REI market than most of the country, at least as far as I've found.

I have applied the majority of what you wrote due to the trial and errors I've had in the past.  

The key for me has been (through trial and error unfortunately) finding 2 good contractors who I can be almost entirely hands off with and leveraging some basic technology so I focus most of my time and attention on finding deals.I've found that in order to do a decent volume of houses the vast majority of my time and attention needs to be on finding good deals, since that's the hardest part of this.Having really solid contractors who can make some minor paint/tile/house layout decisions and do a decent job with it has been crucial.Also- leveraging basic technology- for example I have a part time employee I pay to go around to all my rehabs once per week to take 5-10 minute videos and upload them to my google drive.

Trial and error.  

They built their business through trial and error. 

I just go to a clinic whenever someone needs a drug screen. 

Trial and error was the best thing for me, however, it got frustrating after while and I finally reached out to my local Real Estate Investor Club.