Touching the head of a Thai is very bad. In Thai culture, the head is the highest part of the body and it is not easily forgiven when a Thai touches another Thai on the head. In a similar way, the feet are the lowest part of the body. It is rude to point your feet at somebody, so when sitting. Thais cross their legs. It is also rude to step over someone's feet or to touch people with your feet.
There are certain beliefs about gift giving. Golden flowers are gift giving flowers whereas blue and black flowers are for funerals. Thais will accept chocolate, fruit and flowers for gifts. Shoes are important in Thai culture, it is not good manners to walk in shoes in someone else's house unless they are wearing shoes.