There are two schools of thought about writing (in the most general terms). The school that says that you must wait for the muse to come by and give you inspiration. And the school that says you should sit your butt in the chair and write even when the muse is vacationing in Florida. As with anything of this sort, I think the truth is somewhere in the middle.
Getting writing done is a lot about getting in the groove. That sounds a lot like waiting for the muse, except that getting in the groove is something that you can control. You just have to figure out how to find your groove reliably. Because unlike your muse, your groove doesn’t go on vacation.