Hoping to "Step Up" My Photography in the Future

That is I'd like to improve my photography. I've sold photos and sometimes do take some nice ones, but compared to the work in 52Frames, the facebook photography group I'm in, I'm in the basement. But I'm not quitting. The theme/challenge of the last week in 2014 was Stairs, and here's my picture:

I realize that I must get out of the old "film is expensive" mindset and take many more shots of the same scene. This one should have been better; it could have been better.

Here are a few I took but rejected for "Stairs." Did I err?