Most common way to get around is on those red shared taxis (called Songthaew)

In Chiang Mai, you'll see a lot of cars that look like this:

• It's called Songthaew (pronounced like song-tau)
• They usually just drive around along the main streets in the old city, Nimman, and other tourist hot spots (e.g. the Zoo)
• From what I've seen, they're one of the most common ways for tourists to get around because they're cheap and readily available. They're literally everywhere. Honestly don't worry about not being able to find one if you're in any sort of major tourist area
• I've used them a few times. How's how:

1. Know the name of the destination you want to go to. The drivers probably know all the major and no-so-major points of interest
2. Just raise your hand to hail it if you see one driving down the road (like you would a normal taxi back home)
3. If they stop for you (sometimes they're full, or reserved by a small group so won't stop for you), go up to the driver window and tell him/her your destination
4. Agree on a price. I've seen many of them labeled 30 baht (~1USD), but I was told this is the price for less than 5km. In any case, the price will vary if you're in a remote area (like if you're at the temple up Doi Suthep mountain) and there's not enough people. To give you a sense:
5. My ride from Nimman road to the Zoo (~2km) was 30 baht , and it was just 2 of us
6. The ride from the Zoo to the Wat Phra That temple up the Doi Suthep mountain (~12 km) was 50 baht per person and there were 3 of us
7. The ride from the Bubing Palace down to Nimman (probably ~18km) was 150 baht per person for 2 of us