My pointing system:
5 Excellent design, excellent placing, excellent idea
4. Good design, good placing, good idea.
Excellent idea, good design, ok placing.
3. Good design with a Good/excellent idea, but I don't like the placing.
Great work with a good placing, but I don't get the idea or it just doesn't move me.
2. Good design, but I don't like the placing and/or the idea.
Great idea, but I don't like the design (ugly works with potential).
Good basic work with an idea that doesn't move me.
1. I don't like the design.
0. This shouldn't be here. It's not printable quality.
Mostly if I recognize that I don't understand some concept, I usually just skip the design. If the design is good work, I might give it three points. To a concept, which I don't understand, I don't want to give 0-2 points, because why give bad points to designs if I'm just too stupid to understand?
$ I will give to a design with 4-5 points (if I want to buy it :)).