大方的adj.=generous, one of this meaning is that one person is willing to give and share. Its synonym in Chinese is 慷慨kang1 kai3，its antonym is 小气xiao3 qi4、吝啬lin4 se4
Example: 她很大方，捐了很多钱。She was generous to contribute lots of money.
The other meaning of 大方 is that not rude, be polite in manners and behavior.
Synonym: 自然zi4 ran2 =naturally , antonym: 忸怩niu3 ni4、拘谨ju1 jin3 =shy
Example: 女主人自然大方地迎接客人 The hostess greeted her guests with ease.
潇洒= natural and unrestrained，so in this way this two words are quite different from each other. Although this word could be used both on women and men, I prefer to describe a man with this word.
Example: 英俊潇洒ying1 jun4 xiao1 sa3（describe men）