In order to create you need to free up some time just for writing. This is a time when your mind needs to be clear of all outside influences. For me that is first thing in the morning, while my husband is still asleep and the dogs are outside.
This time should be as stress free as you can make it. I try not to get online, until I have written as much as I can for the day. Sometimes, this is only a few minutes. I can't force the words... They either come or the don't.
As the day goes on I try to think on my characters and where I want them to go so that when I sit down the next morning the words flow. This is the same when I get a prompt... I think on it before actually sitting down to write.
I don't actually form the entire story until my fingers hit the keys, but bits and pieces of the story float in and out of my consciousness as I go about my day. If the images get overwhelming, I might pull out a pen and paper and write if I am not near my keyboard.
I carry a tiny little composition book in my purse to jot down ideas and I am not often without my notepad when I go places. It is always better to be prepared to write then have to make do on a napkin or an envelope.
My head is full of voices, all clamoring for attention. It is through my writing that I let these out so I can make room for the next characters. I think that is why I am so enamored of Flash Fiction...I can let the characters find their voices quickly and then the next character will be good to go for the next story.