You look (adjective)

If someone is dressed or made up nicely, you can tell them so like this:

You look great.

You look amazing.

You look gorgeous.

You look really nice today.

When is OK to tell someone that they look good? In general, women can say this to other women. A man probably shouldn't tell a woman that she looks nice unless they are dating or in a relationship.

(something) is smashing

"Smashing" is a fancy-sounding word that means "great" or "wonderful". You can use it to talk about things that are very successful, very fun, or very beautiful:

A: How did it go?

B: It was a smashing success!

That dress is absolutely smashing!

"Smashing" is a little uncommon. In most situations, we use other words like "wonderful", "great", or "beautiful" instead.