Don't use too many colors in your logo or it will be very difficult to reproduce across many types of media. 

Pay attention to the shape of your logo and think about where it will be used most. Will it fit in the media that you're hoping to use? Is it too long? For apps, this is especially important. 

A logo is meant to be instantly recognizable. Make sure that you aren't subconsciously copying a competitor and make a logo that stands out from the crowd.