Honestly, your technical knowledge doesn't necessarily matter that much in interviews. The best way to get better at interviewing is to interview a lot. The most important skill for interviews is usually the ability to tell a compelling story. If someone asks you how you have solved problem X before, how well can you tell an interesting and insightful story to answer that question?
It's amazingly rare to get asked hard technical questions or be required to write code during an interview.
The more you interview, the more you become aware of what your weak points are. After the interviews, immediately dig in and learn more about the questions that stumped you. Over time, you'll have good answers prepared for the common questions you are being asked. Don't sweat the questions that don't come up often, your competition isn't likely to know the answers to those questions either.
Don't underestimate the need to be able to talk comfortably and knowledgeably about software development processes like agile development, continuous integration, etc.