If you're waiting to get into the mood to write, you may be waiting for some time. It's best to make a writing schedule and stick to it - in the mood or not.
Harry Crews, the American novelist, gave similar advice. He reportedly said:
You can’t wait to write until you’re in the mood. My God, if you waited until you were in the mood, it would take forever. You have to sit down. The name of the game is to put it in the chair.
Of course, because nobody's perfect, some days you're just not going to be in the mood and, consequently, you're not going to write, but those days should be infrequent.