I just took the course offered by MilesdividendMD, and are beginning to become a "churner". I opened the Chase Sapphire preferred, as well as a Target Redcard account to process the gift cards I"m buying. This is my test card to learn how the process goes without f#$ing things up. It is going very smoothly at the moment.
My next step will be to apply for 6-8 cards at once sometime in the next week or two, now that I feel confident. I have an excel file where I'm creating the churn, to map out what it will look like from a logistics standpoint.
Basically, it's a lot of fun. I'm getting a kick out of the whole thing.