Its easy to feel a bit dazed when you get through customs in a busy airport, especially when you are assailed by hopeful porters and taxi drivers. We accepted the services of a man, only to find that the deal included the driver and a potential "guide" - and the fare was US$12, rather than the advertised US$8 - we were in the car, with luggage before we realised it.
We were also quoted very high prices for guide service, and road travel around Yangon.
Unique Suggestions: Walk outside the airport, rather than letting yourself be solicited inside, without an understanding of who is involved in the journey! Also, make sure you don't get IN the taxi until you've discussed the fare.