Depending on the situation, you can drink Nihonshu chilled, room temperature, warm or hot. Simply, you can pour it in wine glass and enjoy with meal. Or if you have any Japanese traditional sake instruments, they would make the sake taste even better.
Usually, people in Japan drink Shochu on the rocks with a dash of water. You can also drink it mixed with hot water in the cold winter day. For multi distilled Shochu (Kou-rui), you can mix it with lemonade, flavored soda, fruity juice or tea. (They are called Chu High in Japanese)
Very similar to Shochu.
On the rocks, mix with soda water or hot water or making sake cocktail.