I discovered this feature not long ago and I saw some people around here not using it. I think it's a quite obscure feature but sooo useful. I think putting in the "tips of the day" and the wiki won't be enough; I think if Arcen changed the subtitle "fleet command" into "the galaxy map is hand-editable" it still won't be obvious enough.
I changed two controls in the "galaxy view" and it changed my life (I'm no more afraid of realistic map style!). To get them, hit escape, click "view controls" then "galaxy view" then on page 5 of 6 define keys for "switch to official galaxy layout" and "switch to my alternate layout" to your liking. I defined PageUp and PageDown, for instance.
Now, when on your alternate galaxy layout, you can shift+drag'n'drop planets. Also setting the "open galaxy layout menu" key let you see the layout of other players (if you play multiplayer).