1. read others code. think. ask questions. why and how certain code is written in certain way.

2. Read more code.

3. Write more code.

4. If your code which you wrote few years back looks bad to you, then you are on right path.

5. How much you understand the core concepts. New languages and frameworks are more of an glitter.

6. You want to be better version of yourself, then your progess is your stats you need look at. How many books did you read year on year? How much code you read year on year ? How much code you wrote ? How much fun you had :)

7. Adding, if you can think of the future maintainer of your code in mind and code, then you are lot better than many programmers out there in business.

8. Try to be a clean code enthusiast.