Software engineers should avoid some common and simple mistakes like having zero knowledge of what they are doing and directly coding, instead one should try to gain complete information of what they are doing. Over complication of the code can also cause issues while writing the code, try to keep it simple by following some principles like KISS and YAGNI. Try to write some unit tests along with your code it helps you a lot in improving your coding skills. Be positive-minded and optimistic by opening yourself for suggestions that will improve your skills