Open source projects seems to help if you know what to look for (like search for top 10 android project/plugins/whatever) - breakdown each part you would like t

Open source projects seems to help if you know what to look for (like search for top 10 android project/plugins/whatever) - breakdown each part you would like to learn (architecture/codeStyle/asyncTasks/compatibility/images/UI/tests/perf). Concentrate one at a time.