I once received an email from a student who was going to be taking AP Studio. He was responding to suggestions I had made on his ideas for the concentration section of the studio portfolio. I was blown away by his response and level of thinking on how he took my thoughts and digested them, then took off in a new, exciting direction. He wrote that he'd seen an old, abandoned bedpost and was thinking of salvaging it and "just maybe based on the idea of modern society through the lens of the whole altarpiece type feel" he could use that idea and his love of art history (proudly, another class I taught that he was in and received a 4...)
My response was long-winded, and I realized I was revealing more of myself to him (and myself) than I had planned - but I kept going anyway. He was also concerned about being excited with the concepts but afraid he didn't know enough technique to pull off the finished work. My response: I hear what you're saying as far as technique. That will always be a fear (and should be to challenge you). You can do this - just keep looking at art.
I have become completely addicted to looking. While I want to do everything I see and wish I could have the time, I learned something when I was in advertising many years ago - I can't be the best at everything. I realized I would never be the best painter, drafts person, whatever - but I knew I was really, really good at how I approached a concept and could follow it through.
That's my talent.
One of the reasons I have had such a difficult time returning to the studio is that I was trying to do what I have always done - creating the still-life images I have sold for years. My fear: am I still good enough? Will these still sell? My reality: I am different now and don't want to do the same things I did 10 years ago. My love of sketchbook and deconstructing has led me to experience and experiment with materials and a "quickness" I never thought I could do. I don't approach every piece as if it has to be in a gallery (and I can tell you many would never make it...) but what I've discovered is what YOU are supposed to discover in doing a concentration.
What you are capable of - what you truly love and are interested in. The rest will follow.
Technique is about practice...again and again, and again. Concentration is about concept and how you THINK over and over again.
Art has a purpose other than placement on a wall behind that chair...it allows you to see inside who you are and how you perceive the world. Even if you never show your work to anyone else. It's the journey that is the adventure. Not the destination.