Compost bins are composting within a structure of some sort. This can be a box, bag, trash can, wooden container, or wire fencing. There is an almost unlimited number of composting systems out there and this is just a couple that you can do yourself.
The classic free and easy method is to make a compost bin using pallets. Pallets are used to ship goods in bulk from one place to another. They are found in stores, factories, and warehouses. If a person can locate a source of pallets a single or multiple bin system can be built with just a few nails or screws.
A single bin requires 3 pallets which are fixed together to form a box with the front and top open. The open areas allow easy access for adding compostable materials, turning, and watering. You can close the front or top if you find the bin unsightly but it is not necessary.
Adding additional bins to the system can give you a collection bin, working bin, and a finishing bin all of which will be in varying stages of decomposition.
Large trash cans make great compost bins. They are completely enclosed and have a lid so pests are not a problem. The only addition that they may require is a hole or 3 drilled into the bottom so that excess water can run out or collected for compost tea. The cost of these will depend on the size and brand of the trash can being used. Once again you can use just on or have several going at the same time.
Wire is another cheap method of creating a compost bin. Galvanized chicken wire can be formed into a large upright tube shape and when fixed together. Tie the ends together using wire and you've got a homemade wire compost bin that can be reused for years.
These are just 3 possibilities. What one person has readily available might be almost impossible for someone else to find. Look around your home and neighborhood for ideas of what might work for your situation.
If building one doesn't seem to be right for you than other options are available include buying a compost bin, lasagna gardening, and building a compost pile.
Making a compost bin is an easy project that can be customized by what materials are available. There is no right or wrong way to do it as long as it can hold the waste material of the kitchen and garden for composting. Once built all you have to do is start adding your compost greens and compost browns and sit back and wait (well you should turn it once in awhile).