Well managed compost is one of the best things you can add to your garden, plus it's also the cheapest, if you do it yourself.
Composting doesn't necessarily mean that you must have a large smelly pile of rubbish that takes years and years before it becomes usable. It also doesn't mean that you have to go out to the back forty with a pitchfork and turn the compost pile to get real compost. Today there are multiple options when it comes to composting. Before talking about the different ways of composting, lets look at what is compost.
Humus is the most valuable soil amendment a gardener can add to the soil. Composting is the production of humus from selected garden and kitchen wastes. Microbes break down organic raw materials into humus, as they do leaves on the forest floor. Composting is a great way to get rid of yard waste and improve soil structure with no negative impact on the environment.
Humus is organic matter in a form plants can use. It adds small amounts of nutrients to the soil. It improves soil structure, water-holding capacity, and nutrient-holding capacity. It costs almost nothing to produce and diverts yard waste from landfills.
Humus has an advantage over applying unprocessed organic matter such as fresh grass clippings, garden debris, leaves, sawdust and wood chips directly into the soil. As these organic materials are broken down my microbes, they consume nitrogen.
Nitrogen is the single most important nutrient in plant growth. As the organic matter decomposes the microbes are taking nitrogen from the environment, so, if these organic materials are placed directly in the soil, the microbes will take the nitrogen directly from the soil, and thus causing nitrogen depletion in the soil and your plants will suffer.
If the organics gathered into a pile the microbes will take the nitrogen
from the organics themselves. 
This microbe activity heats up the pile during
the decomposition. Temperatures can be as high as 160 degrees at the peak
of the process.
In time the decomposition slows and finally stops. At this point the organic matter is no longer clippings, leaves, and wood chips, but a dark brown or black material called humus.
There are multiple ways of making compost. The simplest form is just making a pile of organic matter and let it sit. This will take several years to completely break down. If you mix or turn the pile, it can be usable in less than a year. Trench composting is a slightly modified method of pile composting.
A step up from basic pile composting is bin composting. This is basically a pile compost, but one that is confined by something that helps concentrate the microbe activity and increases heat levels. This method is more efficient and you can convert a pile of organic matter into usable compost in as little as 1 month depending on how much effort you put into turning the pile. The more the pile is mixed, the faster the results.
For faster results there are compost tumblers. These are usually enclosed containers that can be rotated to mix the organic material. Quantity of compost these tumblers can handle goes from just a few cubic feet up to about 18 bushels of material at one time. Since this equipment is usually enclosed and vented, it cuts down on the possibility of attracting nesting rodents. The efficiency of mixing the pile speeds up the process greatly.
The following accelerated formula is designed for open bin composters. It is essentially a way of boosting the environment for the tiny microbes living in the compost pile. The best way to speed up the compost pile is to make sure the pile gets just enough water to keep the pile moist. This means during rainy days, protecting the pile from getting too much water. During the hot days of summer, it means adding water.
Follow the above advice and then once or twice per season you can add the following chemical booster to your pile, work it in and turn it.
Add a 1-2 shovels of regular dirt to the compost pile surface,then pour the liquid mixture gently over the entire surface of the pile. Give it a few minutes to soak in and then turn the pile as you would normally do.
The ammonia provides extra nitrogen for the microbes. The yeast in the beer will help boost microbe growth and the sugar in the can of soda proves additional carbon for improved microbe growth. The shovels of dirt provide new microbes to the pile. All together and it becomes a great place for microbes to begin digesting all the organic matter in the pile. That digestion process will soon convert your clippings and twigs into dark, rich organic matter that you can add to your garden areas.
