Generally speaking, Thailand is a more conservative country. As such, spaghetti straps and daisy dukes are not recommended to wear, even in the bustling streets of modern Bangkok. When visiting the temples especially, there is a strict dress code. Make sure to dress appropriately by covering your thighs (to your knees) and shoulders and showing no cleavage. This applies to both females and males. Shoes also need to be removed before entering many places. Buying a cheap sarong from a market stall in the city before you set off on your first day is a great idea. You can then quickly wrap it around you when needed and fold it up small to fit in your bag. You can also use it as a blanket when visiting the beach.