If you are speaking to a man then it would be:
You are beautiful (to a stranger) - Vous êtes beau
You are beautiful (to a friend) - Tu es beau
If you are speaking to a woman then it would be:
You are beautiful (to a stranger) - Vous êtes belle
You are beautiful (to a friend) - Tu es belle
If you want to emphasise it then you can also use the word très (very) before the words belle and beau.
You say, belle cousine.
Reste belle is how you say stay beautiful in French. You can also say: "garde ta beauté, garde ta fraîcheur which also means stay beautiful.
"belle maison"
beau desastre
belle âme
"Belle femme" is "beautiful woman" in French.
Belle famille is beautiful family in French.
Beautiful skin in French is "Belle Peau" :)
Beautiful photographs in french is de belles photos
Belles personnes is "beautiful people" in French.
'Beautiful view' translates to French as 'belle vue'.
Beautiful all over in French is belle partout.
Beau Rêve = Beautiful Dream
You say, belle cousine.
cloche
belle
Beautiful Goddess in French is Belle Déesse and is pronounced (Bell dee-eh)