Your Camry uses a coil over strut type suspension.
The proper method of lowering a vehicle like this involves replacing, at a minimum, the entire coil/strut assembly with springs designed to lower the car (which are both shorter and stiffer), and uprated struts that will handle the increased forces imparted by the springs.
Additionally, especially on higher mileage vehicles, it is a good idea to replace suspension components directly affected by the lowering, as the new suspension geometry and increased forces will wear out already worn parts even faster. Examples of these include upper and lower control arm bushings, trailing arm bushings, tie rod bushings, sway bar bushings/endlinks etc.
If your car came with various trims levels that offered a sport suspension package, you may be able to simply swap those parts over. This has the benefit of being able to use OEM components, which are guaranteed to fit and may be cheaper than aftermarket
Lastly, after any suspension modification, the car must be aligned! This is the step that many people skip and the cure for almost all of the negative handling characteristics people associate with lowering a car, like a steering wheel that tries to dive into ruts in the road. A proper alignment will put your steering geometry back (or at least much nearer) to factory settings.
Pros: Looks, improved handling, marginal improvement in fuel consumption
Cons: Ride quality will suffer in a direct relationship to how aggressive a drop/performance increase you want. Car may scrape over speed bumps/steep driveways. Increased crash damage, as bumper may be too low to be effective (Personally rear ended a car in a lowered Integra. The other car had almost entirely superficial damage, whereas the mine was totaled, with catastrophic damage to the radiator support and surrounding areas)