I usually have a pre-made set I’m going to play so that solves that problem!
Save that, you could use pencil and paper 😛
If you want to get a bit more creative, you could have multiple very short playlists (like 4 tracks) that you’ve practiced mixing between. Make sure no song gets repeated in these playlists, then essentially mix between these mini playlsits. This will give you a bit more freeform vibe, it’s easier to remember or at least less to write down (I’ve played trance list 5, for example).