There are two basic kinds of drywall compound; powdered and ready-mix. Ready-mix compound (Image 1) is pre-mixed and only needs to be stirred with a paddle to use. It must only be used in a 55 degree or higher climate so that it will dry properly. Apply bullets Powered compound (Image 2) sets-up in a specific amount of time, rather than by temperature. It's available in various drying times.
Use a knife to scoop compound out of the bucket onto a hawk or into a mud pan (Image 1) for transport to the wall. Apply a small amount of the material on a knife. Run the knife along the wall at an angle, using two fingers to put pressure against the back of the knife (Image 2). Continue to mix the material while working by turning it over occasionally with the knife. This process is the same for either kind of drywall compound.