Fresh ideas are not always the best ideas (although they may seem like at the time)

Basically, don’t immediately start working on a ‘big’ idea you just had. Sleep over it and start comparing it with other ideas to see where its value lies. Sometimes you can be so excited about a ‘perfect’ new idea or solution that you don’t see its shortcomings. Remember, design should not only be judged by the problems it solves, but by the problems it creates.