As an imperfect creature, I commit mistakes, and I also try to avoid them. Here are a regular ones, I hope to not repeat them, but it seems it's hard to learn your lessons sometimes...
# Git
* Always double check the text of your commit message, before, during, and after pushing it.
* Always double check the diff of your commit, before the commit, and after pushing it, that way you make sure you didn't cause a mess for later.
# Writing and Communication
* Always double check your texts via grammer checking tool before sending important communication.
* Always double check the message you are answering to, before making conclusions or reacting in a hurry.
* Always double check the spelling of the name of whoever you discuss with before mentioning them so you don't offend them.
* Double check your sources.
* Keep it simple.
* First say thank you when people are trying to help you, ask you something, or suggest you something. People take from their limited time for you, don't neglect that.
* Don't propose solutions/help too early especially if not asked. Many people prefer also to learn and solve problems by themselves.
* Let it burn. Sometimes that's the best you can do. Don't try to extinct every fire. Focus your energy on the problems that really impact you. There are enough solutions and people for the other problems and you don't have time for them all.