That depends on how you want to run your business and how you want to be viewed by your peers (and the better business bureau etc).
Sure you can walk into every home, lock it under contract for 5K below retail and then post it on Craigslist and Facebook, every time it fails (Because it is not a deal.. but instead is a listing with no realtor to work it) pull out a reason why you can escape and leave the homeowner with lost time and confused. I would assume your reputation would hit the bottom pretty quick and investors and buyers will start to avoid what you list because they do not trust it. (Go on Craigslist in your area and look for the one person who listed 30 properties in 20 days and nothing since you may find many)
From what I understand (no expert) but you should make sure you understand market value and repair costs above all else. When you see that deal that you would tell your grandmother to sell her medications to invest in because it is that good, jump on it. You will find a buyer with no problems. If not you should start talking to grandma because you want in on this one bad and will make it work yourself. Your job is to lock it up when it is in the best interest of the seller to get it done quick and the buyer can make a decent amount of money on it while still paying you a nice sum for finding it.
If you are looking for a way to take zero financial risk yourself you will find the risk is actually your reputation which costs more in the long run. Start researching your area, learn the values, get with a mentor, go to open houses and window shop, find contractors and get into discussions, get an idea of what sheetrock and insulation costs. Practice viewing properties in your area and run numbers.
Just my 2 cents and best of luck