/ic/, how do you politely tell someone irl that their art is horrible and they need to do anatomy studies badly?

I know this guy at Uni through a drawing class I took for fun who draws worse than a 12 year old, but wants to be a professional artist. It's so bad that when he does studies, he gives the people animu proportions (he copied a man with a massive head and tiny body, completely ignoring what the study actually looked like)
Usually people like this are complete arses, but this kid is a nice person and I really don't want to see him crash and burn. He's completely oblivious to the quality of his art since the professor just gives him asspats for whatever he does; the prof never requires him to do better. (maybe for the same reason I haven't, because it may offend him and alienate him from improving)

How do I convince him to start doing real studies and reading books without offending him? I wouldn't just go up and say "your art sucks", but I'm unsure if a "you need to work on this, this is how you can improve" will work.
What do?