An important carpentry lesson to remember is to pay close attention to details. There are so many things that can be looked over or forgotten on a carpentry job, such as running out of material or out of supplies maybe you forgot to add in the brace you wanted and the list goes on. Train your mind and eyes to look for details the more details that you can remember in a basic carpentry job the better carpenter that you will become.
Keep your mind clear and on your work. I made many mistakes in my carpentry apprenticeship because I would think of other things besides my work while I was working. The more focus that you stay on your work the carpenter that you will become. There is an old saying "BECOME ONE WITH YOUR WORK GRASSHOPPER”
Another important lesson to remember is to be observant and aware of your surroundings. If you are working around others be aware of what they are doing, this helps you to visualize what comes next on the carpentry project that you are working on. And again it will help you to become a better carpenter.
One reason why people do not become successful in basic carpentry is because they allow people and situations to distract them to often from there work. Learn to love carpentry to the point where you are not going to let anything get between you and it.