A designer has to be as alien as possible. Since each thinking entity thinks in different frequencies, every design evolving from the soul of the designer has to be different, so different that it has to be alien. But why are they not? It is because of the influence of inspiration. When a design starts evolving, the platform of the design unfortunately remains earthly. So the end design shares appreciable number of characteristics with the inspiration.
This happens when the design has a common noun, that is for example, an automobile. But when the design is just a design, the true picture of the spirit reflects as art. Now this is beautiful. Splendid designs potray the characteristics of the spirit of the designer, just like an x-ray. This can be followed in the above case by keeping the mind as blank as possible and letting the spirit play on the blank canvas. The result will be undoubtedly splendid, more importantly alien.
To put it in nutshell,
You do not need the box to think out of the box