Inspiration comes from so many sources. Music, other fiction, the non-fiction I read, TV shows, films, news reports, people I know, stories I hear, misheard words or lyrics, dreams... Motivation? The memory of the rush I get from a really good writing session - even on a bad day, I know I'll find that again if I keep going.
Give me good writing, and I'll play it all day.
Good writing is supposed to evoke sensation in the reader - not the fact that it is raining, but the feeling of being rained upon.
The most important thing is to read as much as you can, like I did. It will give you an understanding of what makes good writing and it will enlarge your vocabulary.
The secret of good writing is to say an old thing in a new way or to say a new thing in an old way.