The thing to do also, go on your computer at night & look at the arrivals for the airport you are going to for the next day. It will give you an idea of how many flights are coming in and what times.
The queue is guaranteed larger trips if your mindset is to hit a certain dollar in a day just sit there and wait for $15or better trips with a short drop off 30 mins max so you don't go too far away from the airport its way safer than driving into the inner city and bar scene for pickups fares are usually dollar per minute in most cities