Simply say "I like your outfit" or "You look nice," and leave it at that.
According to the provided reference, the key is to keep the compliment simple and direct. Avoid over-elaborating unless she invites further conversation about her clothes.
- Keep it short: A simple compliment is effective.
- Respect her response: If she wants to discuss her clothes, engage. If not, move on to another topic.
This approach shows you appreciate her style without being overbearing. It opens the door for further conversation, but doesn't pressure her to discuss something she might not want to.