C&C per req:
1. Overexposed by probably 1, 1 1/2 stops, additionally, note that the bloom isn't actually in focus, but rather the leaves behind it are. Manual focus is best for doing close-up/macro work, but if you do auto-focus always be cognizant of where your camera is focusing.
2. Focus on this one is much better, as is the exposure. It has compositional issues however; the blades of grass in front of the bloom are distracting, as is the ground underneath.
3. This one isn't bad. I think it would have worked better had you been shooting "down" a little more, rather than parallel to the table. Note that the background, while soft is still focused enough to be distracting.
4. This one is very nice; good selective focus to isolate the subject, nice array of textures. On suggestion would be to have composed this in such a way that the lines in the wood were going front to back rather than side to side; this would have directed your eye to the flower.
5. An interesting idea, but a little soft.
I hope you don't perceive that as harsh; it's not meant to be. You have some good images, and I think a good eye, it's just a matter of training it to see the technical issues in an image.
Just my $00.02 worth - your milage may vary.
~John