5GinFIRE is a Research and Innovation Action project under the EU programme Horizon 2020. It offers an open and extensible 5G NFV-based ecosystem of experimental facilities for third parties, selected through open calls. 25+ successful experiments, focused on a wide set of heterogeneous topics, have been executed so far over the 5GinFIRE infrastructure. The purpose of this whitepaper is to share some of the mechanisms that have permitted to conduct such an important amount of experiments over 5GinFIRE. On the one side, testing workflows were defined so that participating actors, roles, capabilities and offered services were clear for the incoming experimenters. On the other, schemes to develop, on-board and deploy experiments were designed to improve the availability (and repeatability) of 5G tests.