In a boutique.

If a sales person asks "Est-ce-que je peux vous aider". what is the best response if you you do not have anything in particular to look for but are only looking or browsing?

You could say "Non, merci" with a "Je ne fais que regarder" or "Je regarde, c'est tout" (I'm just looking).

Bonjour! Très bien toru! Often when I go into a shop and somebody asks me that question, I often asnwer, "Non merci, pour l'instant ça va." All of the responses above are also commonly used. Keep up the good work! - Marie-Claire