Docker Engine is plenty of commands. There are more detailed cheat sheets out there (e.g., this one); here I just try to put together some useful commands/tips I usually need.
docker ps
(appending -a lists all)
docker commit CONTAINER_ID TAG
docker stop CONTAINER_ID
docker rm CONTAINER_ID
docker rm $(docker ps -a -q)
docker images --tree
docker rmi IMAGE_ID
docker rmi $(docker images -q --filter "dangling=true")
docker rmi $(docker images -q)