[Rivière]

If you're short on cash, you could do the traditional chocolate approach as a safety net, that's if she likes chocolate. If not then think of something you know she has and likes, perfume, a type of clothing, body care, moisturiser etc etc. If you're wanting something more deep and meaningful then what you could do is spend time with her and listen to her talk a lot, find out what she likes by making conversations about specific things and getting into a really good chat about them. If she likes gaming, talk about games, "I can't wait for blah blah to come out, how about you?" if she likes perfume, "That perfume smells really nice on you, do you like a lot of perfumes similar to that?" See where I'm going with this?

Just having conversations like that can easily help you find out what she likes without giving hint as to what your intentions are.