Singapore 

In formal situations Singaporeans cross their legs at the knee and it is considered very rude and impolite to allow the foot to point at someone or move things with one's foot

Hitting the fist into a cupped hand or touching someone else’s head is also very impolite

Finger gestures such as pointing or making the okay symbol with your hand is also very impolite

Public displays of affection are rare but are becoming more common among the younger generation 

Hosts always offer something to drink, because it would be impolite not to

Invited guests are expected to be punctual and if the host or guest gives a gift, it should be opened later and not in the the giver's presence