Creating interesting effects in camera doesn't always have to require expensive filters. With a little ingenuity and a cheap UV filter, you can replicate these cool effects in your own work.
First, grab yourself a cheap UV filter; you don't want to use a more expensive one for any of this, and certainly, never put anything directly on your lens. The second thing to remember is that taking advantage of some of these effects requires you use a wide aperture; otherwise, you'll just get weird image artifacts. From there, it's time to get creative! There's no certainly no set correct way to use these techniques, so experiment to your heart's content; start conservatively and build up the effect to taste. If you go the Vaseline route, remember since it's hydrophobic, you'll need some sort of soap to get it off; I recommend hot water and dish soap or simply throwing the UV filter in the top rack of the dishwasher.
Just a note: while this tutorial is oriented toward filmmaking, all of these tricks will work perfectly well for still photography as well! Do you have any cheap DIY hacks you use for interesting visual effects? Share them in the comments!