I tried what I called Visi-spells when I used to play D&D.
Fist of power = hand from a broken doll on a wire stand
Ice wall = cut bit of clear plastic (corridor wide) with glue smeared on & a thin wash of Tamiya translucent blue paint.
Distance viewing = Large bead on a stick, painted up as a giant eye-ball.
Magic bridge = Strip of clear plastic (cavern crossing wide) with magic symbols drawn on with permanent markers
Various scare spells = parts from a repurposed broken Halloween (6" tall) toy.
You get the idea.
I much prefer there to be something pretty on the table than player saying that their wizard casts ...
Plus if you can get the 'Wizard' to make the spells you get to know what spells are coming.
