I myself am still trying this challenge, but I have found that a really simple infrastructure on the ground consisting of, a crane to stack, a way to open and close fairings and put payload in using the same vehicle, and something to refuel. This challenge is a lot of stuff to take in. All the stuff on the ground and trying to land and fly a second stage at once is very difficult. Not to mention recovering that second stage. But making this challenge as simple as possible makes life so much easier, as you have to worry about less vehicles and less things going wrong. And the time your saving by having to test less vehicles and giving you more time to focus on your flight.