Compost happens in nature as well as in your own compost pile. The difference is that in nature, the process may happen over months or even years. In your own compost pile, you have more control than Mother Nature does. Because of this, you can speed up the process. Turning organic matter into dirt quickly is a simple, controllable process.
Chop all of your compost pile ingredients into smaller pieces to give the microbes in your compost bin more of a surface area to decompose. You can chop food scraps with a food processor and run over grass clippings, straw, leaves, hay and pine needles with a lawn mower. Large pieces of wood can be reduced to smaller chips with a wood chipper.
Mix equal parts "green" nitrogen-rich material and "brown" carbon-laden material in your compost pile.
Aerate the compost by poking holes into the sides of the pile, constructing your compost bin so that there are holes in the sides of it, or ventilating the compost with a piece of perforated PVC pipe.
Keep the pile moist, but not wet.
Turn the compost every day with a pitchfork to further aerate the compost and to move decomposed material from the center of the pile to the outside, and undecomposed material from the outside to the interior. The more frequently you turn the compost, the faster it will aerate.