The main rule of thumb for picking circular saw blades is to pick the right blade for the job. Some wood blades are designed only for certain types of situations. Use a ripping blade for an extended cut that follows the grain of the wood, and don't use it on plywood. A crosscut blade is what you'll need for that job. There are many types of blades to choose from, including framing blades used for construction projects, and diamond-abrasive blades which can make cutting up to 30 percent faster. When buying your blades, many online vendors offer a cheat sheet displaying the type of blade with its approved applications listed. Consult this sheet before buying and you should have no trouble getting the proper saw blades for the job.