You should bring an open mind with you along with a good sense of humor. Don’t come up with too many preconceived ideas about what Thailand looks like, because the media and the experiences of friends have a habit of distorting reality.
If you stick to big cities and tourist areas, don’t worry too much about too little packaging; you can find all the essentials you have forgotten. This includes a swimming costume, a daypack, an umbrella in the rainy season, and some warm clothes if you are traveling in October/December, as it gets cooler in some areas. Some sources say that there is no point in bringing a mackintosh during the warm rainy season because it is so hot and sticky that the mackintosh becomes uncomfortable.
You only need a few clothes to change, as you can get washed cheaply everywhere. Sandals, if your hiking boots are too hot, you can buy them cheap in Thailand, although large sizes are harder to get for women. If you are female and you wear the size 2 (US), size 6 (UK & IRL), size 36 (rest of EU), it can be difficult to find clothes that will fit you anywhere in the Thai shops. If you are male and have a waist of more than 38″, you will have difficulty finding trousers. In Bangkok’s shopping centers, you will be largely limited to backpacking gear (the ubiquitous fisherman’s trousers and “Same Same” t-shirts) or Western imports at the same or higher prices as at home. Laundry is cheap, but it’s a good idea to bring some clothes to change, as the Thai weather can make you sweat through several outfits a day.
Bring enough padlocks for each double zipper so that your hands don’t wander around and you can lock your belongings in your hotel room. Close zips through the lower holes, not through the upper ones on the pull tabs – although even this precaution doesn’t help much if you run into a razor-blade artist.
Take snorkeling gear with you or buy it on arrival if you plan to spend a lot of time in the water. Or hang up a note looking for equipment from someone who is just leaving. A tent for camping is a good idea if you are a National Park fan, and a compass is also a good idea. You might also want to bring compact binoculars if you are into wildlife. Having a proper map of Thailand is also useful.
Bring earplugs if you get stuck in a noisy room or want to sleep on the bus. Bring a mirror for shaving, as often there are none in places with a low budget. A string is very handy for hanging up laundry. Cigarette paper can be difficult to find, except in tourist centers. Climbing boots are useful for rock walking since Thailand actually has some of the best cliffs in South East Asia.
If you have prescription glasses, it is a good idea to bring spare glasses or contact lenses and a copy of your prescription. Bring a book that you are willing to swap. A personal music player is great, as there is a huge selection of cheap music available everywhere.
Throw sunscreen and insect repellent in the toiletry bag. Mosquito coils are also a good idea. A small torch in pocket size is handy when the power goes out or for exploring caves. Passport photos are very useful for visas.
If you plan to travel long distances by motorbike, you should buy a high-quality helmet, which you can do in Thailand. Last but not least, you should pack your things in plastic bags so that they don’t get wet, especially if you are traveling in the rainy season or on boats.
Apart from the points mentioned above, the following points are recommended:
- Prescriptions for prescription drugs that are brought through customs
- Travel Insurance
- Blood donor/blood group identification card
- Details of your nearest relatives
- A second photo ID besides your passport
- Credit card plus a security card for a separate account