I've also adopted the idea of creating a manned lander/mission vessel and then slapping a probe core on it to test things out first. I don't want to lose any Kerbals in 23.5 now that I feel like I am a competent mission planner and pilot. For my longer mission that I am planning to Jool I am sending up a science lab and habitation module, unmanned, first to set up a space station. Even though I don't have any life support mods I self impose a certain amount of realism to any of my missions.