A few thoughts:
1) Jazz guy might be a little more "gritty" and "engaging" if you convert to B&W and been up the blue channel a bit - but play around. The loght and color is just a wee bit plain.
2) LOL..love the pic of the girl munching on the apple. Now, I can appreciate it for what it is - not planned at all, which makes it spontaneous and more "real". I think it's fun and not modeled - seeing her eyes widen in surprise and perhaps burgeoning chagrin?...hehe.
She may feel that a better positioning of the apple and her mouth might've made the image a bit more flattering of her and not made her look like a bit of a glutton..lol.
The crop - where her hair is cut off - could perhaps either be lowered or lifted - the slice you've cut off is just a little bit too thin in my opinion.
From a pure aesthetical point of view, that big black hair - probably from her coat - sticking to her nail and reaching across her upper lip, probably shouldn't be there.
However, the pics a great as they are, since they are "real" and they are candid and particularly in the case of the young lady, it' makes it more memorable. So it all depends on the objective and what you are aiming for - so take my comments in that spirit.