Be Easy to Work With
Clients most of the time value a lot how easy it is to work with, sometimes even more than your musical expertise. It is one of the biggest nightmares for any producer/director etc. to work with a composer who isn’t able or willing to communicate properly, has a big ego, doesn’t want to make compromises, misses deadlines, is unreliable etc.
So as a composer you should make sure that you make the collaboration with you as smooth as possible (even if your client doesn’t act the same way). People will remember a good collaboration experience. And even more: people will remember bad collaboration experiences even stronger. So it should always be a high priority to give your client a good feeling when working with you.