Always write for yourself. Writing to impress or flatter others or even thinking about what other people will think while writing the song, can lead to a short or long-term case of songwriter's block. Think ahead to what you want your end goal to be, from your eyes about your reaction to how great the song is instead of from your friend's eyes and their reaction. That way, you can figure out how you want the song to sound. In most cases, writing for others instead of oneself happens when you've already played an original composition for this person and you want to make sure this one is up to par by imagining the worst possible reactions and changing your song to fit them, when you truly value someone's opinion and you will be playing this piece for them, or when you're writing a song for your band and you're afraid they won't like it, because the last time they didn't like your composition, you blew up and asked if they could do better, which led...