If you need to find someone who can speak English and you’re not in a tourist area, go to a pharmacy. Pharmacies are almost always staffed by licensed pharmacists and you can’t graduate from pharmacy school in Thailand without using English.
If you read or hear “lemon” or “lemonade” in Thailand, then 99.9% sure it’s a lime, not a lemon. For some reason, most Thai dictionaries and schoolbooks teach the word lemon and not lime. Actual lemons (má-naao lŭuang or má-naao fà-ràng) are very rare in Thailand and never used for cooking Thai food.
If you’re extra hungry you can order a large portion of most Thai dishes, from pat thai to tom yam gung to lâap, for a few extra baht by telling the server pí-sèet (พิเศษ).
If you can’t find your destination on a train timetable check for it with Ban, Muang, or Nakhon (all of which are a version of “town”) in front; for example Nakhon Lampang. Also, imagine the name broken into parts. For example, the unusual spelling of Lop Buri instead of the normal Lopburi.
If your hotel has a cheap electric shower water heater that doesn’t warm up enough even when the temperature dial is turned all the way up, you can increase the temperature by lowering the water pressure. If there’s no hot water at all, there’s probably a circuit breaker somewhere in the room that needs to be turned on.
Pack a power strip. Hotels rooms usually have few electrical outlets (cheap guesthouses often have just one) and they’re often in inconvenient locations. So, with a power strip, if you travel with lots of items that need charging, you are covered for both capacity and distance.
If the person at the desk of any Tourism Authority of Thailand (TAT) visitor center does not know the answer to your question, ask them to get somebody from the back. The people staffing the desk are usually just university student interns.
Men’s public toilets at temples, rest stops, etc. usually have urinals hidden in the back.
If your hotel uses a key card to cut out the electricity when you’re not in the room and you want to charge your electronics or keep your laptop running, use the outlets for the refrigerator, which often have constant power.