1. Failure to start with the basics.
We are often guilty of thinking that we already know the basics of something and this then leads to us skipping reading the instructions and just getting stuck into it. The problem here is that we are often slightly deluded and misjudge our own capabilities or see it as some kind of a weakness in having to go right back to the start. However, it is essential that you read instructions or take small steps from the outset in order to build a firm foundation and the task, or job, you are doing will then become easier and you will be better at it. Get the foundation wrong and you will continue to make the same mistakes and be completely unaware that there is anything amiss leading to you failing to improve over time.