#6 Be Persistent
There will be times that it takes literally a dozen requests to get someone to a meeting.   Keep asking.  They may come to a meeting, or tell you they can't join now because they are too busy or they aren't interested in joining at the moment.  These are all fine answers as long as you keep track of them and keep in touch.  Ask them to an event or to participate in a project.  This can be a low key approach to showing them what they are missing.