How could you increase the rate of a chemical reaction?

The collision theory states that when two or more particles have sufficient energy and orientation, the collision will be successful in producing a reaction. There are many ways to increase the rate of a chemical reaction - increasing the surface area means that there are new surfaces being exposed, meaning a better chance for reactions; increasing the concentration means more particles are available for reactions; increasing the temperature means that the particles have more energy and more speed, and are more likely to collide; adding a catalyst can also lower the activation energy (the minimum energy needed for a reaction to take place), and can also be removed chemically unchanged.