“Do unto other flying club members as you would have other flying club members do unto you.”
I saw this in action yesterday when a plane came back from flying and needed fuel before the next flight. Line crew were already gone for the day (as they typically work from 13:00 to 16:00) and three members were in the office chatting. These three members rallied to help the next pilot fuel the airplane, so she could get on her way.
Generally speaking, the returning pilot should re-fuel the airplane and put it back in its parking place if line crew isn’t available. That is, if a pilot returns early in the morning and another flight is scheduled to depart before line crew arrive, the early pilot should re-fuel and have the plane ready for the next pilot to take. Similarly, if a pilot returns in the evening and the plane is scheduled to fly the next morning, the returning pilot should re-fuel and have the plane ready for the morning pilot to take. All it takes is for each club member to be mindful of when the next flight will be, so that the airplane can be ready to go.
The bottom line is that if you want an airplane ready when you get there, leave the airplane ready-to-go after you bring it back. The Golden Rule (of Flying Clubs) results in positive member engagement, aircraft that are ready-to go, and overall happier members.