Although manufacturers of compost activators and those who sell their products would like you to believe you need to buy their activator for your compost to work, this simply isn't true. Organic material will compost whether you add activator or not. Of course, activators may speed the process, but there are other natural materials you can use that work just as well and are absolutely free. So before you spend your money on a commercial product, take the time to look around for natural items you can use.
Begin with a compost pile or bin with ample amounts of both wet and dry materials. As a general rule, the ratio of dry to wet should be 3 to 1. Experts disagree on an exact ratio. The best judge is your own compost bin. If the contents are too wet and begin to smell, add more dry material. If it is too dry and fails to compost, more green material is needed. Layer material so you have alternating layers of wet and dry material.
Use manure as a natural activator. Not only will it speed the decomposition process, it will add nutrients as well. Use care to add plenty of dry ingredients like leaves, dried twigs and shredded wood to keep the pile active and prevent the pile from becoming too wet.
Sprinkle ordinary garden soil between layers of your pile. Healthy soil is teeming with microbes needed for your compost to break down into soil. Take advantage of its natural ability to activate your compost pile.
Activate the new compost pile with fresh compost. This makes an excellent starter, much like yeast starter is used to activate the growth of new yeast.