Create a filter

So the other day I was thinking about filters and effects... I don't like photoshopped filters or effects, and even though I'm shooting new school digital, I prefer to do most things old school. So, I may not be able to add my effects in the enlarger-->paper process, but how can I do it in real life, and not in a photo editing program? It obviously called for some experimenting time.

I started with some plastic wrap and dish soap and was quite unsuccessful in producing anything I thought was interesting. Then for some unknown reason, I decided to try nail polish on a plain protective filter... and again for some unknown reason, I choose a polish I don't think I've ever worn, one that has a clear base and large purple glitter flakes. Here's some things that happened...
(holding filter away from lens AND from object, somewhere in between the two, focusing on filter)
holding filter near object
filter near end of lens, looking up near sunlight
filter not far from lens looking directly into sunlight
no sunlight or flash, lit with lamp from behind, filter near object

If you notice, none of these were taken with the filter actually screwed onto the lens threads, as I was unable to get anything in focus when it was attached. Just a fun experiment, nothing more, nothing less.