How Do I polish my android development skills? [closed]

Question

I know much more than basics of Android. I have already used all basic classes available in android. But still sometimes when I see some of the applications, available in PlayStore, I feel that I'm not expert yet, in fact I'm much away from it. I strongly feel Learning when someone teaches you is much better than just self learning. I want to expertise in

1. Developing/Designing beautiful GUI for Android Apps
2. Effective Coding - I can implement most of the things wiht the help of code available somewhere on net, but when it comes to customization, I struggle a bit. Need to improve coding skills so that product has most effective piece of code.
3. Get comfortable with the new additions in API (e.g. Action Bar)

P.S.

I'm working as an Android Developer for past 2+ years, I have worked on various apps involving use of sqlite, SOAP based web services, Google Maps, GPS, Calendar API etc.

I have never studied core java, preparing for my SCJP certification these days.

Please provide your tips, and the approximate time I will need to get a feeling or confidence that I'm Expert or near Expert Android Developer.

Answer 1

I would concentrate on your SCJP first.

If you have the full understanding of Java under your belt, making use of that as an Android developer will be easy.