When I was at school in London, England, studying for my masters in communications at Antioch University's London program, many of my fellow students would talk up their stories, but never sat down to write. They spent their time pubbing and seeing the sights of the great city. They felt that they would sit down and write when the muse hit them.
Now, I had no problem with visiting the tourist areas. I did plenty of that in the two years I lived there, but I was also focused on my craft. I spent most of my free time at the British Museum Reading Room - a wonderful place similar to our copyright library -- with original manuscripts from Richard, the Lionhearted and William the Conqueror. (You have to get special permission ahead of time if you want to use the Reading Room, but it's well worth the effort if you are serious about researching the time period of your story.)
I learned quickly that the muse didn't just hit you, you had to train it. I did that by writing every day - it didn't matter if it was good, it didn't even matter if it pertained to the story I was working on - but I wrote. I set up a time for my muse to visit and was religious in following that. Soon, "she" not only visited when I asked, but stayed on for longer than my anticipated writing schedule.
While many of my fellow students in the master's program wasted their time, I was one of the few who not only had my work published, but who managed to make a decent living from my writing after I graduated. In fact, I don't know if any of the others achieved their goals or not.
The important thing I learned was that you had to be focused on your craft and be willing to make mistakes.
I remained focused even later when I had to return to a day job. On the bus going to work, I read and took notes, at lunch - instead of going to the cafeteria I brown bagged it and ate quickly using the rest of the 45 minutes to write (this was helped greatly by having an outline for my story and knowing where I was and what had to be put into that new chapter or scene), and rather than going for drinks with my co-workers afterward, I went home and wrote. The muse found me all during that time and rather than flitting in and out, came at my beck and call. As a result, I seldom suffer from writer's block.
We can all carve time out of our busy schedules and train the muse to come to us. Be focused and persistent, outline your stories so that you know what you are saying in that chapter or scene, plan your writing time - even if it means getting up a half hour earlier or not watching television that evening. If you really want to write, there are no real excuses. You, too, can train the muse to come to you when you need her.
Happy Holidays to you all and may your writing be wonderful this year and for many years after.