When should I hire or contact a contractor?

[Parker Smith]

Hello all, I'm a newbie to real estate investing and my biggest uncertainty so far is when to contact, hire and how to deal with contractors. I've asked for recommendations for GC's in my area and have contacted them and asked for referrals from their last three clients. I'm not in a position to buy right now, but I am trying to get ahead of the curve and get my feet wet with dealing with contractors. 

When you were first starting in real estate investing (BRRRR or flipping) when did you contact a contractor?