Determine the type of mat you would like to cut. Traditional mat cutters make straight incisions, but there are also varieties that can make circular incisions.
Decide upon the size of mat cutter that best fits your work location and production needs. Mat cutters are available in many sizes and shapes, from small mat cutters that resemble knives to large computer-run systems. The advantage to smaller systems is they are more portable and space saving. The disadvantage is there is more room for error. The advantage to a large system is the ability to produce more mats. The most commonly used mat cutter is a tabletop variety, which secure to a table to provide a firm, even surface for mat cutting.
Search for information and reviews on specific brands. Reading the reviews of other people can help you decide which features are needed and which are not. Ask friends or co-workers which brand they use.
Visit your local art supply store and try different varieties. You may find you like the look or feel of one brand compared to another.