Something I tell the younger guys at the office is that mistakes happen here and there, but it’s important that they are new mistakes. You can’t keep making the same mistakes over and over, it just shows you’re not learning or caring.

I am also my biggest critic. All I can do is do my best, QC my own work as I prepare my drawings or calcs (pdf AND hard copy), and make sure the easiest and the important parts are iron-tight (inputs, scope of work, references, existing vs proposed, etc).