Where do your ideas come from?
What a splendid, stress-inducing question!
I do love this question as it shows the person is genuinely interested in my work and makes me feel impressive. Then I open my mouth and think, "You're about to sound very unintelligent." I fumble through some nonsense about atmosphere, eternal truths, and organic thought. As the Question Asker's eyes de-glaze they say, "Well, I can't wait to read it!" and we end the conversation.

Oceans and...

Honestly, I've never really thought about where my ideas come from. I thought they just came. Sometimes I force myself to come up with whatever happens next because it's time to write that scene and ideas are no longer allowed to hide. Sometimes I'm writing a scene and someone new walks in, someone I've never met before, but there they are, waltzing in all living and breathing right in the middle of my story. Mostly I listen to music and dream it up. As lovely as these examples are, none of them actually answer the question, where do your ideas come from?
But the other night I had a realization of sorts. I went to a party in Brush Prairie, WA(read: soggy farm land). When I was leaving the party I walked onto the porch and felt the night.
The rain had relented. The deep night sky peaked starless through white clouds and a cluster of mammoth pine trees reached out to me with long, piney fingers.
I descended the porch steps to the field-like lawn and tried to find the stars. When I moved my head the clouds seemed to seep across the sky, but when my head was still they sat still as well. As I stood in the cold, wet air nodding my head at the clouds, I heard a playful sound in the trees to my right. When I looked to the trees I was struck by how frightening pine trees are at night. Peering into the deep black bows I imagined what monsters might have found their perfect hiding place in their branches as the oddly childlike tune of the trickling rain drops held my scariest thoughts at bay.

...xmas trees always give me ideas. Always. 

Just then, I heard someone coming out of the house so I quickly took it all in again. The melody, the dark hiding places, the red-light-green-light clouds, the inky sky, and the wet, wide field. I'm saving you for later, I thought.  And they all sighed with relief because they made it. I cared that they existed and I put them down here. They will each live forever in words written and read.
I've known since I was a teenager that I see the world slightly differently. Things like oceans and Christmas trees are significant and it is very important that I pay them the attention they deserve.
I used to think my ideas Rolodex consisted mostly of nature, but it turns out I notice and save everything. Things like selfishness, judgement, tent cities, brothers-in-law, tiny hands, and cups of coffee so warm and comforting '"it's like drinking a blanket."
Which reminds me, I steal almost everything from you. That last line was not written by me, but said by another writer I know. Sometimes I take your words(with permission, of course) and sometimes I take you and mix you with my favorite parts of books: kindly monk figure(Brent Stahl), strong and reserved young woman(Tess Stern), young knight fighting for justice(the serious House Church Leader version of Matt Solschied), unaffected chick who could easily kill you(Annalise soon-to-be Southwood)  happy-go-lucky, take-on-the-world, true-to-the-end best friend(Brett McLean).
And that's where my ideas come from. Everywhere. But only if I'm paying attention.