I prefer to leave/drop everything I need in front of the door. This way, even if I'm in a hurry, the door just won't open without picking up whatever item(s) it is that I need to take with me (paperwork, umbrella, notepad, etc.)

A couple days before going on a trip, I start making a pile of things to take. As I remember things, I add them to the pile. It has reduced the problem of forgetting things.