A few of tips for making/using magics:

1) Make the paper tile size larger than usual (I make them double than their real size), so that when you are printing them on paper and choosing "fit on page", the quality (dpi etc) will be much much better.
2) get a paper punch for accurate cutting. If you can't, use a previous accurate paper as a reference when cutting with scissors.
3) When stringing, ALWAYS align the papers properly. One mistake would be enough for one paper tile to be misaligned to a different angle making the puzzle look amateurish.
4) Place the string connector (of each string) in the middle of each plastic tile, and if possible, each side of a tile will have exactly one string connector. Trust me, you don't want to have a connector near the side, it may break! Of course movement may move around a connector, but that is a different story.
5) When using ANY magic, and realize that there is some stiff movement in certain parts, try to stretch it a bit and bend it up and down to those parts and release the pressure.

Of course, no one is perfect, but the above help for optimal improvements!