Clean the surface of the wall or ceiling where you plan on applying the drywall mud or stucco. Scrape it clean of any burrs or inconsistencies with the trowel, and use a broom to sweep the surface of debris. Ensure that the drywall has already been taped if you are working with a new construction.
Add water to the drywall mud or stucco until you have the consistency of wet peanut butter. Thin the material down until it will still retain its shape but is runny enough that you can spread it with ease. Add silica sand to the mixture if you would like a more grainy texture.
Grasp the handle of the hawk in your off hand, scoop out a portion of mud and apply it to the flat side of the hawk. Use your trowel to move the mud from the hawk to the wall or ceiling. Spread the mud with your trowel in multiple directions, allowing the blade to "skip" along the surface as you apply pressure and "burn" the mud onto the surface of the wall or ceiling. Move the trowel in different directions to create a varying level of textures based upon your personal preference.