Hi guys! Midio here!
I'm one of the winners of the Heroic Voxels Contest and I also happen to be one of this contest's judges! I've been taking a look at all the forum entries and WIP posts and I gotta say there are lots of awesome stuff being made! Keep up the amazing work! We have 10 days till the deadline (June 22nd), so there's still plenty of time to develop and model cool stuff!
Here's a couple of personal tips and advices that might come in handy!
1) Try to stick to a story and solid concept.
If your model is already done, take a step back and look at it from a distance: what is the story I'm telling? Is it clear enough, is the message easily conveyed? If you have Sketchfab Pro, use the annotations to create your own story, and if you haven't, try using something different: maybe you can duplicate your model to tell us how that terrible mad scientist machine went wrong? Why not try to make a 3D comic strip? Be consistent to your concept.
2) Know your limitations and work with them
Sometimes, it's important to know what are our limitations and deliver a great result within those boundaries. After all, creativity only happens when we have those solid constraints, right? That's where the challenge comes from. If you don't know much of 3D lighting, try doing a well modelled piece and playing with Sketchfab's light. Or maybe character modelling isn't your thing, but you can rock on environment. Try using your strengths to your favor! If you want to push yourself a little further, do it, but work your strengths out and let us see it!
3) Don't overdo
When doing art, there's always a little thing here and there that might be changed, and we would tweak things indefinitely if we could- that is, until someone tells us the deadline is near. Focus on delivering something in the last 10 days!
4) Don't fear that your work is not good enough
You know, contests are made for everyone, and there's pros and amateurs joining and you might fear your work won't meet "the standards". DON'T. Your work might be just as good as anyone else's. My Heroic Voxels entry was my second voxel model and one of the few 3D models I ever did (as I work mostly as a 2D game artist), and turns out it made me get the 1st prize.
So trust your work, work on your limitations, stick to a concept, don't overdo and don't fear your work is not good enough.
I know there's going to be AWESOME models for us to judge, so keep up the amazing work and I can't hardly wait to see them all Rock on!
Best, good luck, and lots of love