I tend to keep an eye on the time and when we’re getting closeish to end time, say something like “Ok, here’s the last scene I want to get to tonight and then we’re gonna wrap up, unless there’s anything we didn’t get to?” – this lets everyone set their expectations to wrap up the last bits cleanly, and is also a better moment than the very end to negotiate whether you want to spend time on something that you did, indeed, forget about now or wait until the next session, IME