Definition: Muse - a person or personified force who is the source of inspiration for a creative artist.
However, it is true that most creative people have something like a muse - call it what you will. It is the spark that is the inspiration for a never before seen way of putting words or musical notes or colors together.
I looked up Muse in Google images and it appears that all Muses are lovely, as in the picture above. I don't know how we know that since no one I'm acquainted with has ever seen one. Maybe we simply believe that any entity caught up in knowledge and beauty and spirit would naturally be beautiful.
I don't know if my muse is attractive....I don't even know if she is a she. My writing is more masculine than feminine and I relate to my male characters much more than my female characters so maybe my muse is a man. We aren't personal friends. The only time he wants to communicate with me is when I am asleep. He can be a little snarky. If I have a column idea but am having trouble fleshing it out, I try to explain it to him, he says, "go take a nap, I've got this without any help from you."
He probably resents being assigned to be my muse instead of say, James Patterson or Diana Gabaldon or John Scalzi. John Scalzi (who has sold millions more books than me and made millions more dollars so you'd probably be wise to try his suggestions before mine) says that when he needs his muse to help him out, he takes a shower. He stands there and thinks about nothing, letting the soothing water massage his skin until his muse (who must be a water sprite) makes her presence felt.
Another writer I knew could not get inspiration indoors. She had to be out in nature. The ideas would come and she'd take notes, then bring them in to transcribe into her computer. (This was several years ago so maybe she takes a laptop outside with her now.
I don't know that I believe in muses. I think it is whatever allows you to ignore the part of your brain that is always busy with everyday concerns in favor of the part that drifts dreamily, opening itself to new thoughts. In other words, I think we are our own muses.
On the other hand, it kind of nice to think of this other entity inside your head ready to take over for you when you don't feel up to the job. I think I'll call mu muse Reno.