Feedback, What im used to and what i want

To be quite honest the only feedback that i have ever received in my life was from kids in high school who were reading my high school writings. People know that kids in high school don't really give you all the feedback you need, or any feedback for that matter. So, the effectiveness was really irrelevant for me because i never really got any real feedback. Now, if i was to sit here today and say what kind of feedback i would want it would have to be mostly about grammar, mechanics, and punctuation because those are things that i struggle with sometimes. So if i could get feedback obviously about the things that i am struggling with it could help me understand it better and help me not to screw it up the next time i write. The only thing i don't want when it comes to feedback are people who find the tiniest little thing that you forgot to do and make it a large deal. I just want feedback on the really important things that i may have forgot to do or didn't exactly do the right way, so then i know if i can fix what they are giving me feedback on i will be on my way to being a better writer.