Venetian plaster may look like another type of paint finish, but it's not. And having good painting skills will not guarantee satisfactory results if you jump right into the job. I strongly suggest that you buy a couple of sheets of drywall and practice with different approaches until you achieve the look you want. Experiment with the angles at which you hold the trowel, the length and shape of your strokes, and the amount of texture you create on the surface. Try different finishing treatments to achieve the depth and sheen you like. If you are tinting the plaster yourself, you will also want to play around with the quantity of colorants needed for the color you want.

Clear the room as much as possible, and spread a drop cloth on the floor. You can apply Venetian plaster to most walls and ceilings, but the surface should be flat and smooth. If there are any cracks or holes, fill and sand them first. The surfaces should be primed or covered with flat paint. Glossy paint surfaces can be plastered over as long as you first sand the surface lightly to remove the sheen. Read the instruction on the can of Venetian plaster carefully for additional preparation requirements

Steel trowels often have very sharp corners, which can leave lines and scratch marks in the plaster. To avoid this problem, sand the corners with 100-grit sandpaper to round them over.

You may want to wear gloves when mixing and applying the plaster, as it can irritate the skin. Eye protection should also be worn if you are spreading it overhead. Mix the Venetian plaster thoroughly before each use.