Looking back over last decade it is easy for me to see what I did wrong and what I could have done better in learning level design and game environments. It is easy for me to say what I could have avoided and where I should have focused my time on.
The mistakes and failures I went through were extremely valuable, even though during such moments it seemed I wasn't going to pull through. In the end, most if not all experiences were extremely valuable and I wouldn't give them up.
But, I do wish someone could have told me a few things to make level design and game environment art creation a simpler process to go through. Certain principles to keep in mind and goals to aim for. So I didn't have to re-invent the wheel. It would have helped me to avoid my first few years starting a project after project and never finishing a single one.
I can think a few people that I know that this applies to, including myself annoyingly, this thing is really worth a good read.
The full article and future E-book can be found at WorldofLevelDesign.com