I usually spend around a day on a scene, and I usually create what interests me, so that always makes it fun.

Here a thing........ Think about something that you are interested in. Build an object (I didn't think I could construct the windmill i've just finished, it was a little frustrating at times, but I managed to finish it) and then create a theme with it. I plan to create quite a few 'windmill' scnes before I start a new theme.

One last point, if it looks cheesy, then it probably is. Try something different... like say what ICM is doing at the moments. Sometimes just rendering a ball with perfect textures and perfect lighting is all it takes to produce something excellent. Just think of the finished product, instead of the road it takes to achieve it.