[Stylist] Advice on how to critique a poem

[Vejas Vasiliauskas]

Hi everyone, 
I would really appreciate some thoughts on this. I'm not much of a poet, only occasionally writing something I keep for myself if I want to express my feelings. I know many of you are poets, though. I'm aware that there are tons of different ways to structure a poem. 
I have some classmates who write poems and feel really unsure how to critique them, even though I listen to my teacher giving them feedback. She'd sometimes ask the student to change a word or a thought, even though that might change the meaning of the poem. Sometimes it seems like their poems are written based off real events in their lives, yet other times it seems that poems can be created with random thoughts and still sound nice. There have also been times where people make upper-case words lower-case, such as "mother" instead of "Mother" intentionally. 
This week my teacher cancelled class and she likes it when we email each other feedback. I feel I don't really know where to start, and would appreciate it if I could have some general advice on how these of you who write poems would like them to be critiqued. I'm sorry if this  email is at all confusing, but I just want to know what to look for when critiquing a poem. 
Thanks, 
Vejas