1.) Comment! Not only does it make the code easier to interpret, but it can also bring logic errors to light as you think through why you implemented something in a specific fashion.

2.) If the language supports error handling (try catch/except) learn it and use it.

3.) Use descriptive variable and function names. Even if it means more typing, the readability is worth the effort.

4.) Use proper code style. Most languages have conventions for style that include what should be capitalized, whether to use camel case or underscores etc.. Learn them and use them.

5.) Write a lot of code. I don't think that there is any real substitute for experience.