Take 2 A4 pieces of acrylic or plexiglass and tape them together with clear tape so they form a triangle.

For the base use a similar sized piece of foam core board or any rigid board. White is best as it reflects the light. Cover this with plastic or put it inside a clear plastic bag.

Tape the top pieces of plexiglass to the base and you have a really useful tent shield to work in. Make sure when cleaning the insides of the plexiglass that you use a wet cloth to prevent the polish particles from scratching the surface.