The following is meant in kindness and because you requested feedback. Please take it in that spirit.
- the titling appears to be off centre enough to be noticeable without needing a measuring tool
- with the pose of the guy on the right, and the critter leaning to the right, and the title off centre, there’s a distinct weight in the composition towards the right, that is not well balanced; you need to improve or rethink this if you want the composition to be more pleasant to the eye
- the critter in the background can hardly be seen, and the texture appears very rough.
- the lighting on all three figures appears very different and makes the group look wrong
- Vicky has dead eyes. They’re not focusing anywhere, not on the viewer, not on something beyond them
- actually Vicky has a very “neutral” expression.
- the texture on the top appears a bit flat; yes there are decorations, but even if it was cotton jersey it might have a bit more “life” into it, the decorations would be standing out too. It should also be sagging a bit at the cleavage if in that pose.
- Vicky’s hair is too flat and static considering her lounging pose; hair would be moving back and away from her face if she was moving, unless she’s done it and is now somehow stuck into that pose while the hair had time to settle, but not fully… if she’d been for a while in that pose the hair would be lurching forwards, either case, it wouldn’t be stuck to her head that way.
- the neck on the guy on the right looks wrong and needs adjusting. So do his shoulders, and the neckline of the t-shirt
- the shoulders on the guy on the left also need adjusting, they are ballooning.
- there is a “halo” around both guys’ head that has nothing to with with a halo effect created by the lighting sources on the hair, and appears to be caused by the original background of the renders.
- skin textures do look quite flat on everybody
- clothing on the guys is very dark against a dark background, this looks muddied and will print (if required) even more so; considering some back lighting effect to bring up the edges or improve the situation somehow.
So, to sum it up:
- rethink composition
- improve lighting and make it more interesting
- improve skin shaders
- add/improve expressions
- touch up clothing and hair so it doesn’t look static or stiff