Every day I pause to narrate what I am doing, for example, en este momento, estoy escribiendo este mensaje, y espero que tu puedas entenderme.
I view myself as making progress when referring less and less to the tools I use for learning. In this manner also, I discover words I commonly use in English that I have yet to learn.
For me by far the most challenging thing about learning Spanish is use of the reflexive and passive "se" as well as the associated syntax. But reading a newspaper might be a better way to gauge progress.