When asked where he gets his ideas, Neil Gaiman often gives the pithy answer, “I make them up. Out of my head.” When a seven-year-old asked the same, he felt compelled to expound a bit (or rather a lot, really, but for my purposes here I've edited out most of it):
“You get ideas from daydreaming. You get ideas from being bored. You get ideas all the time. The only difference between writers and other people is we notice when we're doing it.
[...]
All fiction is a process of imagining: whatever you write, in whatever genre or medium, your task is to make things up convincingly and interestingly and new.
And when you've an idea - which is, after all, merely something to hold on to as you begin - what then?
Well, then you write. You put one word after another until it's finished - whatever it is.”
Daydreaming is a huge part of the creative process. You don't have to stare at a blank page until ideas come—in fact I would advise against it. Gaze blankly out of a window once in a while. Go for walks and stare at clouds. Get lost in your thoughts. Let your inner child wander.
If ever anyone remarks that you look like you're doing nothing, don't be ashamed. Treat it as a badge of honor.