It's hard to skech this kind of idea on paper, so did an additional sketch in MS paint to better illustrate the idea. I ended up directly following the sketches, but they helped me get a better idea of the possibilities I had for this assignment.

Below this I've added images from before and after editing, along with some commentary.

I feel like this is the image that changed the most. As you can see, the original image was very dark. I don't think I could have used this had it not been saved in RAW format, which allowed me to brighten up the leaves without losing their color. 

I don't think it's very realistic for rays of light to appear in this situation, but I like the way it looks.

I really liked this one. It's like someone's discovered this old house, and the only light source is the sun shining through the windows.

There were already some small light rays in here, but I exaggerated them a bit, added some bigger ones, and changed the lighting.

If you're curious as to how I added these rays of light, HERE is a tutorial. I utilized the same basic technique, with some  adjustments here and there.