Regardless of whether a particular tactic - the obnoxious Craigslist one comes immediately to mind - is legal or now, your reputation is the absolute most important asset you possess.  

It was awful because I was trying to build a reputation and was unable to figure out ways to make these leads work. 

As in most cases be careful that the contractors are reputable and GUARANTEE work to new homeowner!

Do a search here on BP for "Rich Dad" or any other type of training you may consider...What you'll likely find is that there are a lot of high-priced, national training organizations out there that have VERY poor reputations.  

Unlike a regular homebuyer, who may have difficulties, your failure in a deal would put you out of business, your livelihood is on the line, you're not about to get a bad reputation over some home purchase!   

Change the area through neighborhood programs, change the reputation of the area, get rid of external issues that keep your rent rates depressed, but all of this take time.

@Ben Leybovich Wait, so, Vinny The Knee Surgeon isn't a reputable lender?

Should I go ahead and find a reputable GC?

You should never be deceptive in your dealings because reputations do follow you.

Have your considered investing with a reputable turnkey provider outside your local market?