The first thing to remember is to never make excuses as to why something didn't turn out the way you planned it. Unless you say something is wrong with it then nobody knows that. But if you feel that your work isn't the best it could have been then don't show it. This is especially relevant when it comes to demo reels. The studio exec doesn't care that you didnt have time to do fur or finish a model and no amount of hand waving and excuses can convince him otherwise that you're capable of doing better if just given the chance.
Blendshapes, SDK's and constraints don't show up in a still render, so why bother with them in the first place? The time you take to do all that could have been used to improve your model. Bones are ok for posing purposes, but why apply SDKs, IK's and blend shapes if you're not even going to use them? Keep blend shapes to just the expression you plan to use for the final image. Prioritize the elements of a project. If it's a still image, don't bother with lots of animation elements. Finish the intended model with textures, then go for the extras.
Render at the angle that best shows your work. Make lots of renders at different angles then compare and contrast them to find the best one. If it's a bad angle then don't post it. Re-render at a better angle and post that one. Putting bump maps and textures are useless if we can't see it in the final render. Optimize your image so that your model fills the space given. Don't post a 640x480 image if your character only fills about a quarter of that.
Arrange the model in different angles. Render a side, front, rear, and three-quarter view to optimize the view of your model. That kind of presentation is actually like a spin animation. We get to see all sides of your model.
Do detail shots. If there's something in particular that you want to show off, then do a close up shot as well that shows the detail of what you did. Don't tell us about the veins or wrinkles in the skin if we can't see them, show us.
Ok, I hope that gives you all a little more constructive information to help you in your future projects so that you can turn out a better piece of work. Good luck!
