One thing I learned from a colleague years ago is: Delete code. If a function isn't working after say 10 minutes of trying, delete it and write it from scratch.

One thing I learned from a colleague years ago is: Delete code. If a function isn't working after say 10 minutes of trying, delete it and write it from scratch. Another thing: walk away, come back, bug fixed. And the other one: explain code to a friend or yourself