around 6am this morning i got bored of doing my own stuff and needed a little refresher, so i did some drawovers of a few of your comps. feel free to ignore them if you wish.
1.a) jamie, honestly i thought this was looking pretty good, but, assuming you are going for a disney princess feel, some of the proportions were a little weird. i raised the waist, shortened the arms, tapered the feet, gave her dress a bell shape and some more mexican dress decoration, added a second flower in her hair, evened out her eyes (they were tilted like asian eyes) and defined her nose as a simple triangle (you probably wont want to keep it, it's just a stylistic thing i'm into).
2. rebecca: i think most of the elements of this merman are trying to portray realism, but then some of them are going stylized? a little more unity and clarity would be nice, but i'm going to press forward as if you mean it to be more realistic.
a, b, c) hairstyle: once again, this 'hair' is a little ambiguous. is it coral, dredds, or long curly Polynesian hair?
d) the end of his spear was round, unless theres a reason why it should be round, keep it flat.
e) i added some more dragon seahorsey fin stuff happening down the tail.
f) i excentuated the shape of the spearhead a little, just to give it some more feeling of manliness, strength and interest.
3. shannon: i'd be wary of a few things with this current scene: the house/environment seems very generic. there are some fun things happening to the house, but should the man living here be friendly or unfriendly? a is an example of what an unfriendly version could look like, b is a friendlier version.
c)stagger the steps more. use them as an implied line to lead you to the focal point, the house.
d) make sure the hole's purpose is clear, and shape language matches that of it's surroundings.
i also just noticed that the house is split evenly roof vs main body. choose one to emphasize and adjust their relative scale accordingly.
i would also not make identical shapes right next to each other (ie. the 2 bumps on the bottom side of the cliff. they are the same size, and the space between is also the same size.
4. stacy: just an example of using that teardrop shape to create your character
these arent perfect, but hopefully someone will find them somewhat useful.