I'm making a guide here for those who want to take up bus-spotting as a hobby.
First Thing you might do is research. For example, you want to ride a Volvo B10M Mark II. Go to sgwiki and research on route deployments. See if your desire-to-ride bus is on which service. Consider the route pattern. If you want to ride a bus on a highway, take all the service numbers that your desired buses are in. Scout the route out on SBS Service number enquiry or SMRT Electronic Bus Guide.
Things you need:
A good bus-spotter would never go out on an empty stomach. Have a sumptuos lunch but don't eat too much. If you are bus-stopping after work or school, have a meal first before you head out. You don't want to have an empty stomach waiting for a desired bus. Bring a snack or two for reserves in case you get hungry waiting.
Next, is judging what time it will arrive. If you are riding a desired bus on a low-demand route, it's frequency will tend to be long (27-59 mins). If you are riding it on a high-demand route, the frequency would be about 5 - 12 minutes. If there's a bus timetable at the bus stop, refer to it.
Bring a camera. If you want to take a picture of the bus, you might want to use a high quality mobile phone camera. It will no cause suspicion among others. If not, be brave if you are taking it on a SLR camera or digital camera.
Lady luck. Sometimes, luck could help you. Sometimes, your desired bus may be on another service, let's say your regular neighbourhood service filled with Bendy buses. One day, you see your desired bus making an unexpected cameo on it. Cameo is a bus lingo meaning, 'a spare bus which replaces a faulty perm bus. Some service timetables require a certain bus to do 2 services back to back.
Choose a comfortable bus stop. Wait for your desired bus to arrive. Just don't choose the wrong bus stop at the wrong time. If you do, the bus captain will be very suspicious.
Be a curious fox. Try to predict which bus would come out first. If you see your bus just arriving at the bus interchange, see what service it's on and spot other buses which are on that service. If you spot that bus was on that service only, you could wait or have a toilet-break. If there's two to three buses, you can have a comfortable meal without rushing. It depends on the service frequency. Try to time each bus departure on the service. I recommend 5 minutes for feeders and 10 minutes for trunk services. low passenger demad services could be timed at 15-25 minutes.
Get a concession or season pass. Use the advantage of unlimited rides benefit. This would save money from wasting it on fares for bus-spotting.
If you have all this, you're on your way to become a good bus-spotter.
