While working with Git, committing seems the easiest part of the job: you add files, write a short comment, and then, you're done. However, it is because of its simplicity that often, especially at the very beginning of your experience, you acquire the bad habit of doing terrible commits: too late, too big, too short, or simply equipped with bad messages.
Now, we will take some time to identify possible issues, drawing attention to tips and hints to get rid of these bad habits.
Too often, I have experienced this scenario. You start to fix a small issue in a file. Then, you see another piece of code that can be easily improved, even if it is not related to what you are working on now. You can't resist it, and you fix it. At the end and after a small time, you find yourself with tons of concurrent files and changes to commit.