Here is an article by Confused Laowai. It starts, “I’ve been studying Mandarin at University for about two years and 3 months. The mistakes I made, might not be mine particularly, but perhaps the way our course is structured. However, these mistakes can be applied to anyone starting to learn Mandarin. These “mistakes” are not necessarily bad, but it’s part of my current shortcomings in Mandarin that I still struggle with. Perhaps you can learn from me and try to fill those gaps earlier on….
He goes on to discuss his 5 Mistakes I Made When I Started Learning Chinese.