I love his hair and face and eyes. Loving that hand, too! XD And the details in the clothes are beautiful *w* ! Now for some advice/guidelines that you wanted XD hahahahah~
1. Someone probably thought he was a girl because his chest was poking out or something. xD That is a no for guys. Unless you purposely gave him boobs.
2. The human body doesn't have straight lines.
biggrin Someone told me to make my arms less pointy.. So don't let that happen to you!
3. He srsly needed a butt. xD Someone told you this before I think. Yes, guys have round butts. Some of it can be hidden by his shirt, yes.
4. His thighs were like, crazy short compared to his shins. xD They should be near the same length~
5. I forgot to put the five. Direct your attention to that curves arrow thing near his right leg! It should have a little curve at least. I shouldn't be straight even though it's a stylistic choice maybe? :3 Iunno, but if you start off drawing certain parts straight because it's part of the style, you won't understand the basics~
6. I think this is the desired angle for the foot. :'0 I drew some diagrams for you, too!