By "a natural sounding way ", I suppose you mean "Japanse-Japanese（日本人が現実場面で話す日本語）" or "Not-English-Translation-like Japanse(英語の翻訳臭くない日本語）”.
>for example if you have a choice between 2 cakes and you wanted your friend to pick which one they want?
Let's assume here the name of your friend be "よしこ(Yoshiko)".
Then I suppose one of the options you could say would be:
"あ、よしこちゃん、好きな方（ほう）、取って (Oh, you pick whichever you like)”
※ I believe Japanese girls never call their friends "あなた“.
I personally cannot remember the last time I heard and spoke the word "あなた” in my real, everyday life,