1) Make sure you accept all pool trips. More riders in your car, more $$.
2) East bay is where you want to be at. Specifically Concord, Walnut Creek, Dublin/Pleasanton area. Rates are lower yes, but lots of rich people who tip and its easy to drive there.
3) If youre in the city, typically SOMA is where you want to be at. More pool trips towards your 60-75 trip quest.
Also remember to give water bottles and candy for good ratings.