CSS Tips - Graphic Design/Web Design

A poster/infographic I designed based off of my experience in web development class. 

A level-headed approach is necessary to correct mistakes made in CSS - you can't always see exactly why there's an issue right away, but taking a thorough look through your code will usually turn up something you overlooked. I found when I had made mistakes in my code, they often were easily found using the same methodical search every time. Sometimes I got wrapped up in making sure the new tech worked, and accidentally slipped up when working through the basics - like making sure I was using the right file. I figured this might be useful for others learning CSS for the first time.