This is a fairly quick design to do and I have painted it in several rooms. This whole room and the ceiling was painted in 5 days and rather than making a room feel dark which some people worry about it actually makes a room feel huge. You really get the impression that you are standing on a planet with all of space around you!
It can be as realistic or as fun as you like.
This is a variation painted in three days on a toddlers bedroom wall and contains brighter, bolder colours than usual.