Thanks everyone! :)
Aura, as for putting up listing variations instead of separate listings, I've found that potential customers are more likely to click on my item when for example their favorite color comes up in search. So when I have 10 different colors of a hat, I put them in separate listings. Just my experience though :)
And I do see, that the more listings I have, the more views I get, so it's worth the effort to make as many items as possible!