Want to make stuff float without wires or cgi?

While dark colors (especially black) tend to be less visible (particularly against busy backgrounds), other colors will work. The advantages of dark trickline is that shadows actually help disguise it as opposed to give it away, and it blends in with many dark colors. A thin line of any hue against an identically colored background is going to be hard to see when lit properly, but flat black becomes close to invisible against far more surfaces.

Light reflection is the enemy of trickline - any color with a shiny finish is a problem. Since transparent line (like fishline) has no color and theoretically matches any background, one would be tempted to assume it is the ultimate, but in practice clear threads and lines are synthetic materials which tend to be shiny. With light reflecton color becomes irrelevant.

Try to keep any source of light away from casting light onto your lines from behind - thisincreases their visibility as the linephysically blocks some of the light. The brighter the lights, the more careful you have to be, so film with it's light requirements poses a bit of a challenge, but video with its lower contrast and higher light requirements is even harder to work with. As a magician when I work in brightly lit venues, I use other methods aside from thread for performing levitation effects.

If you have to suspend an object against a white background, your approach is the way to go, but darker backgrounds are going to make hiding trickline easier whenever it is possible to use them.

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All the magicians I know that were professionals or knowledgeable hobbyists laughed themselves onto the floor at the masked magician's clunky "explanations", especially the levitiation - hilarious.

While there are many methods for performing any trick, I've never met a magician who actually resorted to using a forklift - it's the last thing I'd do.