Everybody should know about some general and common good manner. So just have a look to this pic and learn good manners. You can enhance your talking and writing with these manners. If you want any grammatical help then you can take help from here.
Mettersi in tiro - "Dressed to the nines" means "wearing very fashionable or expensive clothes". Example: I’m going to dress to the nines tonight because I’m meeting my girlfriend’s parents for the first time.