While there are quite a few things that you could and should pack on your trip to Thailand, there are also a few things that you shouldn't pack or can skip out on.

1. Don't bring unnecessary valuables or expensive jewelry.
   Wearing expensive jewelry just screams "rob me" and it will most likely get stolen plus there is the chance you may lose it so don't risk it and just leave it at home. If there are other luxury or expensive items that you don't need to travel with then also leave those items at home as it is really easy to lose or forget things on your trip.
   
   
2. Don't wear jeans or anything made of jean material
   Jean is a bulky, hot, and slow drying fabric. If you have to wear them then bring one pair and make sure to wear them on the plane to prevent them from taking up valuable luggage space.
   
   
3. Books, especially hard cover or heavy ones
   You are most likely not going to read them while you on vacation and if you are travelling light or are backpacking then they are just a pain to carry as they are bulky and heavy. Some guesthouses and cafe's have little libraries or book exchanges where you can grab a book that you return at the end of your visit or you replace with a different one.
   
   
4. Unless you are camping, leave the sleeping bag at home
   A travel sheet is easy to pack in your bag and with the heat at night, if you need to sleep in just the travel sheet you will be fine. Sleeping bags just take up valuable space.
   
   
5. Skip the mosquito net
   If you are in the bigger cities then chances are you will have AC and no problems with mosquitos inside plus there is a very good chance you won't be able to hang it up. If you do sleep in a hostel or something more remote then the accommodation you have booked will usually supply one if they are needed - make sure to check.
   
   
6. Don't carry too much cash
   ATM are all around Thailand (except the very remote places) and while the fees can be quite high, it is better to use them then carry a bunch of cash due to the risk of you losing it or it getting stolen.
   
   
7. Pack to wear multiple times
   Stick to neutral colours / shades so then you can mix and match your clothing. Unless you are travelling with someone, no one will know you are wearing the same clothes, multiple times. If you can get quick drying clothes then that is even better because you can wash them in the sink then hang them to dry. Clothing is also cheap in Thailand and they are known for tailoring so it could also be a very good reason to shop! One thing to keep in mind is that people dress more formally than you may expect and they have an expectation that visitors should be in clean, business casual items.
   
   
8. Do not pack these "Do Not Wear" items
   To save yourself the luggage space, Thailand is a relatively modest country that does not like to show a lot of skin even in Bangkok. If you are on the beach then swimwear is okay but as soon as you walk away, you should be covered. Make sure not to pack the following items:
   
   1. Short shorts
      
   2. Mini skirts
      
   3. Crop tops
      
   4. Low cut shirts
      
   5. Shirts that expose the bra
      
   6. Cutout tank
      
   7. Wife beater tank / Thin strapped tank tops / Singlet tops
      
   8. Unbuttoned shirts without anything underneath them
      
   9. Anything that looks dirty, grungy, or unkept
      
   10. Anything with camo prints
       
   11. Anything too casual - PJ's, sweat pants, anything stained