I used to live in Riverside and liked flying out of ONT, but usually found it was a bit cheaper to fly from LAX.
However... transport to LAX is not cheap, nor is parking. When you do the math, add in transport and parking. If you live near ONT, then maybe Mom or a loving spouse can take you to the airport and pick you up. You would not have to leave a car there, nor pay for a shuttle. Compare that to the cost of parking and a shuttle if Mom is unwilling to take you to LAX.
While you are doing research, check out the Flyaway busses. They have a Flyaway from UCLA/Westwood. You might be able to get a ride with a friend to UCLA, then take the Flyaway in to the airport. I use the Flyaway out of Van Nuys all the time and like it.