One approach could be to write about how you are using the skills you wish to demonstrate. Yet another Ruby-on-Rails tutorial-in-a-series-of-blog-posts may indeed be boring and superfluous, while you writing about how you built some particular project in Rails might not be.

You could write design descriptions of your projects. What decisions did you make, and why? What was the purpose of the project? Why did you write new code instead of using something that had already been written? Etc.