She hates Sci-Fi, while I love it.
Actually I noticed that she considered Sci-Fi a genre in itself, while I consider it more like a setting, unless it delivers an important plot element (as in H.G.Wells' "The Time Machine").
When Scott McCloud asks for a more diverse offering of genres, it's quite interesting to see, he takes the "genre" principle as a whole.
I myself am now subdividing the idea of a genre, and have found it to be an extremely rich and fertile way of getting ideas, especially when it comes to inventing a different setting.
Actually I split it into 5 categories:
--------------------------------------------Location in Time
When does it happen?
--------------------------------------------Location in Space
Where does it happen?
--------------------------------------------Society
How does the world function?
--------------------------------------------Main Themes
Plot elements? Loose story lines?
--------------------------------------------Mood
Atmosphere of the story?
An example:
Oliver Twist:
---Location in Time:
19th century
--- Location in Space:
London streets
---Society:
The poor often steal to survive; orphaned children are manipulated by criminals
---Main Themes:
Orphan turns to crime...... finds lost family...turns away from crime...
---Mood:
Sombre, but with a Happy Ending
Now when I work the other way round, I get some really original ideas:
an example:
---Location in Time:
I like knights, sooooo...Medieval times!
--- Location in Space:
Somewhere in Early France (got some info about a region), In a castle
---Society:
Feodality, with Troubadours crossing the country and the like and a fear of Demons which surpasses all logic thought
---Main Themes:
A demon possesses the Lord of the castle, who WAS a notorious madman before/ His daughter falls in love with a troubadour come to challenge the Lor, aided by his troupe, and contacts a rebellious group of farmers. Actually he's the Lord's son, and has to kill him to become Lord himself. (a rewriting of some StarWars Elements)
---Mood:
It could be very dark, but the tyroubadour gives me some very nice possibilities to have fun, so I'm making it a Black Comedy!
...Now all I have to do is flesh out the characters and add some subplots to explain their psychologies, and ... Tadaaaaaa!
A quite funny tale about a clumsy troubadour falling in love with a girl he doesn't know is his sister, and having to chase the almighty demon that possesses her Father. (I might add a storyline to make her a real bitch, while a girl from the resistance falls in love with him, which should give sparks and such

I actually work like this, because Scott's "story machine" may work fine, but it has one flaw: it makes me invent stories I'm not able to draw myself.
This way I've got a reasonable control over the story I'm creating, without always going down trodden paths.
Do any of you have similar techniques?
(apart from Scott's story machine, which might still help me in finding themes and such)