Gallery? ... :blink:

cheers,
dr geep
;=]

My color vision isn't really good enough to give you any helpful advice on the skin shaders, although I think the lighting looks a little off. The skin looks sufficiently different from the background that they don't seem to match up.

The composition is a little confusing, too. I see what you're doing with the plants, but the grass doesn't look natural, because it's out of proportion with the plant life in the background, and because it doesn't seem attached to the ground. The background seems very natural, and I can get why the characters are there, but the grass in front seems out of place.

The background looks like it's a photo, and was taken at an angle that doesn't fully show the ground. I think if you move the characters a little bit so that their feet don't show, it'll remove some of the tell-tale blending with the background where the feet are.

If you do another take on this picture, I'd love to see more.

Dr. Geep's is correct, this might be better off in the critique forum or the gallery, but since it showed up here why not comment.  I agree with CaptainJack1 on several points.  The lighting is off on the models.  Notice where the shadows fall in the background image and in your scene.  Completely opposite directions.

The plant material is out of it's element; it does not match the rest of the fauna and is completely out of proportion.  A shrub would have been a better choice. 

The lighting for this scene should be a bit subdued, not too intense.  But there is a fill light to the right which is, IMO, casting an unwanted highlight to the sole of the foot.  If you are looking for a little realism, it shouldn't either be there or the fill light aimed higher towards the face or faces.

I don't know whether you are striving for realism or strictly fantasy, but skin textures could benefit with enhance shading techniques which could be achieved by face_off's Realistic Skin Shaders or BagginsBill VSS Prop system.  It will be interesting to see more work on this.