Teaching is not a discrete toolbox of skills that you quickly acquire and then use as needed. Becoming a good teacher is a long process of trial, error, and success, of talking with others about their teaching, of learning how others learn. Learning how to teach happens like any other kind of learning: you acquire some knowledge, then get feedback on how well you’ve applied that knowledge. Learning how to teach, in short, is a collaborative project.
No matter how many years or how few weeks you’ve been teaching, you can always stand to learn something about your teaching.