Be prepared to shop. I'm not much of a shopper, but Bangkok is the one place on earth that I would actually go back to just to shop, and I've visited the outlets in Italy, the markets in Paris, and I live in NYC. Bangkok has THE BEST shopping.
The Thai baht was slammed in the currency crisis of '97, so the prices are amazing if you are coming from the US or Europe. You can easily find a 3-star hotel for a night, eat for 50 cents, and buy a custom made suit for .
Make sure to stay in Bangkok for the weekend markets, where just about everything that you can think of is sold at incredibly low prices. Too bad I couldn't bring home a puppy.
Quick Tips:
Many people in Thailand speak English, so there is no need to follow a tour group. Bangkok is great for independent travellers. There are ATMs all around the city, and that's how we got all of our cash.
Bargain whenever you shop. If the merchant wants 1000 baht offer 250 baht. Shop around so you get an idea of the prices. It seemed like everyday we saw the prices of things we bought early in our trip, get cheaper and cheaper.
Hawking is a way of life in Thailand, so just politely say no to whatever it is they are trying to sell, or walk away, don't get upset.
Make sure to try a Thai massage. It's cheap and it's great after a long day of walking.
I stayed away from street food, though I now regret it. I do know some travellers that said they got sick eating street food in Thailand, but use your judgement. Drink only bottled or filtered water.
Stay in Bangkok for at least 5 days. There is so much to see and do.Best Way To Get Around:
Taxi's are very affordable, the ride from the airport to my hotel in central Bangkok was just . If you can, find a hotel near the SkyTrain which is the best way to get around Bangkok, it's fast and cheap, and you don't have to sit in the infamous Bangkok traffic jams. Take a Tuk Tuk at least once, bargain hard to get the price down. Take it only a short distance since pollution is terrible in Bangkok.
Don't let the taxi drivers scam you either. If you want to visit a location like Wat Po or the Grand Palace many drivers will tell you that it's closed or not open yet and they will try to persuade you to go somewhere else, most likely a gem store of some kind to buy fake gems made of glass. Insist to be taken to your location, or find another driver. There's no need to worry that the taxi drivers will rob you, Bangkok is very safe, but they will work hard to scam you of your money. Just be on the look out.