Hi, Prectophobia! Since I'm from Argentina, there are expressions which -even though are spanish- I'm not completely familiarized with. That's the case of the first two, "Estar de buen año" y "Estar hasta el moño". Nevertheless, the last one is very common here in our slang. "Estar de punta en blanco" means to be dressed in a very elegant and tidy way; in other words, to be impeccably dressed. Hope my humble help was useful. Greets!

I would also add another sense to the expression "estar de buen año". From my viewpoint, it means being a bit fatter as well, as a direct consequence of having had a good year by means of happiness, wealth, health and/or so on.

"Estar de buen año" is used when you haven`t seen some one for a long time ago and his/her aspect become more healty. "Estar hasta el moño" is being feded of something. and IgnacioV's explanation about the last expresion is ok.